4,144 results on '"Base sequence"'
Search Results
2. Kinetic Analysis of the Base Sequence Heterogeneity of RNA Molecules by RNA/DNA Hybridization
- Author
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Purdom, Ian, Williamson, Robert, Birnstiel, Max, Beermann, W., editor, Reinert, J., editor, and Ursprung, H., editor
- Published
- 1972
- Full Text
- View/download PDF
3. Duplication of Regulatory Genes and Receptors
- Author
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Ohno, Susumu and Ohno, Susumu
- Published
- 1970
- Full Text
- View/download PDF
4. Chromosomes of Eukaryotes
- Author
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Ohno, Susumu and Ohno, Susumu
- Published
- 1970
- Full Text
- View/download PDF
5. Replication of Nucleic Acids on the Basis of A-T, G-C Complementality and the Origin of Life
- Author
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Ohno, Susumu and Ohno, Susumu
- Published
- 1970
- Full Text
- View/download PDF
6. The Genetic Code
- Author
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Peacocke, A. R., Drysdale, R. B., Peacocke, A. R., and Drysdale, R. B.
- Published
- 1965
- Full Text
- View/download PDF
7. Sites of cleavage by restriction enzymes in viral DNAs: comparison of observed and expected frequencies
- Author
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R.A. Elton
- Subjects
Biology ,Cleavage (embryo) ,Models, Biological ,Substrate Specificity ,Restriction fragment ,Random Allocation ,Restriction map ,Genetics ,Bacteriophages ,Dna viral ,Probability ,chemistry.chemical_classification ,Base Composition ,Base Sequence ,Nearest neighbour ,DNA Restriction Enzymes ,Molecular biology ,Restriction enzyme ,Enzyme ,chemistry ,DNA, Viral ,Viruses ,biology.protein ,Bacteriophage phi X 174 ,Cytokinesis - Abstract
Observed frequencies of restriction enzyme cleavage in viral DNAs are compared to those expected from the cleavage site sequence and the known size and nearest neighbour frequencies of the DNAs. It is found that a number of significant deviations from expectation occur, and possible explanations are put forward.
- Published
- 1974
8. The development of the macronucleus in the ciliated protozoan Stylonychia mytilus
- Author
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Hennig W, von Berger L, Dieter Ammermann, and Günther Steinbrück
- Subjects
DNA Replication ,Tritium ,Chromosomes ,DNA sequencing ,chemistry.chemical_compound ,Centrifugation, Density Gradient ,Genetics ,Animals ,Ciliophora ,Genetics (clinical) ,Base Sequence ,biology ,Macronucleus ,DNA replication ,Chromosome ,biology.organism_classification ,Molecular biology ,Molecular Weight ,Microscopy, Electron ,chemistry ,Stylonychia ,Conjugation, Genetic ,Nucleic Acid Renaturation ,Autoradiography ,Ploidy ,DNA ,GC-content ,Thymidine - Abstract
Ciliated protozoa are characterized by generative micronuclei and vegetative polyploid macronuclei. Micronuclei of Stylonychia mytilus contain 1 600 times as much DNA per haploid genome as E. coli. Most of this DNA is shown to be repetitive. The development of the macronucleus involves, as demonstrated by cytology, only 1/3 of the chromosomes which in a first replication phase are polytenized in probably 5 replication steps and appear as giant chromosomes. At this developmental stage considerable amounts of repetitive DNA are still present in the chromosomes. During the subsequent disintegration phase more than 90% of the DNA are eliminated from the macronucleus anlage. The remainder is further replicated five times and composes the final macronucleus. Since this DNA reassociates with a reaction rate almost identical to an ideal second order reaction its kinetic complexity can be determined by comparison with the kinetic complexity of E. coli DNA. Macronuclear DNA reassociates with a kinetic complexity of 26 times the kinetic complexity of E. coli DNA (corrected for GC content) which indicates that macronuclear DNA sequences exist at a ploidy level of 4 096 C. We assume that macronuclear DNA may be present only once per haploid genome. In this case it represents only 1.6% of the DNA in micronuclei or 10% of the DNA in the giant chromosome stage.
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- 1974
9. Specific induction of transitions and transversions of G · C base pairs by 4-nitroquinoline-1-oxide in iso-1-cytochrome c mutants of yeast
- Author
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Fred Sherman, Louise Prakash, and John W. Stewart
- Subjects
Base pair ,Mutant ,Reversion ,Cytochrome c Group ,Saccharomyces cerevisiae ,Cytosine Nucleotides ,Frameshift mutation ,Cyclic N-Oxides ,Structural Biology ,Amino Acid Sequence ,RNA, Messenger ,Tyrosine ,Peptide Chain Initiation, Translational ,Molecular Biology ,Mesylates ,chemistry.chemical_classification ,Base Sequence ,biology ,Transition (genetics) ,Lysine ,Cytochrome c ,Nitro Compounds ,Molecular biology ,Guanine Nucleotides ,Amino acid ,Biochemistry ,chemistry ,Genetic Code ,Mutation ,Carcinogens ,Quinolines ,biology.protein ,Mutagens - Abstract
The base-pair changes induced by the highly carcinogenic agent, 4-nitroquinoline-1-oxide, have been determined from the reversion rates of defined tester strains and from the amino acid replacements of revertant iso-1-cytochromes c . The mutant codons and the base-pair changes of reverse mutations of 14 cyc 1 mutants were previously determined from alterations of iso-1-cytochromes c in intragenic revertants. These 14 cyc 1 mutants, which were used as tester strains, included nine mutants with altered AUG initiation codons, an ochre (UAA) mutant, an amber (UAG) mutant and three frameshift mutants (Stewart et al. , 1971,1972; Stewart & Sherman, 1972,1974; Sherman & Stewart, 1973). NQO † induced a high rate of reversion in the initiation mutant cyc 1-131, the only mutant in the group which reverts to normal iso-1-cytochrome c by a G · C → A · T transition. In addition, NQO produces a significant rate of reversion of all cyc 1 mutants which revert by G · C transversions, e.g. the amber (UAG) mutant and the initiation mutants containing AGG, and probably CUG mutant codons. It did not revert the ochre mutant which contains no G · C base pairs. Ten NQO-induced revertants of the amber mutant cyc 1-179 contained the expected replacements of residues of tyrosine, and ten NQO-induced revertants of each of the cyc 1-131 and cyc 1-133 initiation mutants all contained the expected normal iso-1-cytochrome c . The structures of these iso-1-cytochromes c and the pattern of reversion of the tester strains indicate that base-pair substitutions arise at G · C base pairs which are the site of NQO attack. Thus NQO induces G · C → A · T transitions, G · C → T · A transversions and possibly G · C → C · G transversions. Because of its mode of action, NQO may be useful in less-defined systems for identifying G · C base pairs in mutant codons.
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- 1974
10. HIGH-RESOLUTION NMR INVESTIGATION OF BASE PAIRING STRUCTURE OF TRANSFER RNA
- Author
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Yeng P. Wong, Donald R. Lightfoot, L. Cary, K. L. Wong, David R. Kearns, R.G. Shulman, and Brian R. Reid
- Subjects
Hot Temperature ,Magnetic Resonance Spectroscopy ,High resolution nmr ,Base pair ,Phenylalanine ,Oligonucleotides ,Structure (category theory) ,Saccharomyces cerevisiae ,Arginine ,General Biochemistry, Genetics and Molecular Biology ,Methionine ,Ribonucleases ,Glutamates ,RNA, Transfer ,Species Specificity ,History and Philosophy of Science ,Escherichia coli ,Serine ,Binding Sites ,Base Sequence ,Chemistry ,General Neuroscience ,Tryptophan ,RNA, Bacterial ,Crystallography ,Transfer RNA ,Chromatography, Gel ,Nucleic Acid Conformation ,Tyrosine - Published
- 1973
11. Ribosomal peptidyl transferase: Recognition points on the 3′-terminus of AA tRNA
- Author
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David Ringer and Stanislav Chladek
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Time Factors ,Peptidyl transferase ,Stereochemistry ,Phenylalanine ,Glycine ,Biophysics ,Sequence (biology) ,Cytidine ,Biochemistry ,Chemical synthesis ,Active center ,RNA, Transfer ,Structural Biology ,Escherichia coli ,Genetics ,Peptide bond ,Carbon Radioisotopes ,Molecular Biology ,Base Sequence ,biology ,Chemistry ,fungi ,Substrate (chemistry) ,Cell Biology ,Ribosomal RNA ,Peptide Elongation Factors ,Kinetics ,RNA, Bacterial ,Transfer RNA ,biology.protein ,Puromycin ,Transfer RNA Aminoacylation ,Peptides ,Ribosomes ,Acyltransferases ,Cell Division - Abstract
Current models of the active center of ribosomal peptidyl transferase generally invoke a P-subsite which binds the CCA terminus of peptidyl-tRNA and an Asubsite which binds at least part of the CCA terminus of AA-tRNA [I] . Since the CCA sequence occurs at the 3’-terminus of all tRNAs, it is at least indirectly involved in peptide bond formation. It therefore follows that the elucidation of the role of these sequence in binding to peptidyl transferase sites is a necessary step toward understanding the nature of the peptide bond formation center. One approach which has met with some success in investigating the involvement of the CCA termini of peptidyland AA-tRNAs in the peptidyl transferase reaction has involved the use of N-acylaminoacyl or aminoacyl terminal fragments of tRNA as substrate analogs of the parent molecules [2-l 61. Compounds of this type (e.g., AA-oligonucleotides or AA-nucleosides) can be prepared by chemical synthesis or by enzymatic degradation of the corresponding tRNA derivatives. Despite its complexity, chemical synthesis of substrate analogs for peptidyl transferase offers the important advantage that unnatural compounds, i.e., nonCCA-AA sequences, can be synthesized. The study of such compounds in ribosomal systems can thus enable
- Published
- 1974
12. Complementary regions of the nuclear precursor of messenger RNA
- Author
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Svetlana A. Limborska, Alexei P. Ryskov, and G.N. Yenikolopov
- Subjects
Five-prime cap ,Hot Temperature ,Transcription, Genetic ,Biophysics ,Nucleic Acid Denaturation ,Biochemistry ,Mice ,chemistry.chemical_compound ,Ribonucleases ,Structural Biology ,Genetics ,Animals ,Molecule ,RNA, Messenger ,RNA, Neoplasm ,Ribonuclease ,Sodium dodecyl sulfate ,Carcinoma, Ehrlich Tumor ,Pancreas ,Molecular Biology ,Cell Nucleus ,Messenger RNA ,Base Sequence ,biology ,Temperature ,Nucleic Acid Hybridization ,RNA ,Cell Biology ,Ribonucleotides ,Chromatography, Ion Exchange ,chemistry ,Chromatography, Gel ,Nucleic Acid Renaturation ,biology.protein ,Electrophoresis, Polyacrylamide Gel ,Hydroxyapatites ,Precursor mRNA ,Phosphorus Radioisotopes - Abstract
It has been shown previously that after self-annealing of the nuclear precursor of messenger RNA (premRNA) at high values of Cot about 20% of the material becomes resistant to ribonuclease digestion [ 1 ] . This was explained by the existence of self-complementary regions in the molecules of pre-mRNA and by the ability of these sequences to form doublestranded complexes after annealing. In this paper we report on the isolation and the most important properties of this fraction of RNA (self-complementary RNA or scRNA). Its possible origin is discussed.
- Published
- 1974
13. Formation of rings from segments of HeLa-cell nuclear deoxyribonucleic acid
- Author
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Norman Hardman
- Subjects
Exonucleases ,Hot Temperature ,Base pair ,Haemophilus ,DNA, Single-Stranded ,Nucleic Acid Denaturation ,Biochemistry ,Endonuclease ,chemistry.chemical_compound ,Nucleic Acids ,Nucleotide ,Molecular Biology ,Exonuclease III ,chemistry.chemical_classification ,Base Sequence ,biology ,DNA Restriction Enzymes ,Cell Biology ,Nuclear DNA ,Microscopy, Electron ,Crystallography ,Restriction enzyme ,chemistry ,Polynucleotide ,biology.protein ,Nucleic Acid Conformation ,DNA, Circular ,DNA ,HeLa Cells - Abstract
Duplex segments of HeLa-cell nuclear DNA were generated by cleavage with DNA restriction endonuclease from Haemophilus influenzae. About 20–25% of the DNA segments produced, when partly degraded with exonuclease III and annealed, were found to form rings visible in the electron microscope. A further 5% of the DNA segments formed structures that were branched in configuration. Similar structures were generated from HeLa-cell DNA, without prior treatment with restriction endonuclease, when the complementary polynucleotide chains were exposed by exonuclease III action at single-chain nicks. After exposure of an average single-chain length of 1400 nucleotides per terminus at nicks in HeLa-cell DNA by exonuclease III, followed by annealing, the physical length of ring closures was estimated and found to be 0.02–0.1μm, or 50–300 base pairs. An almost identical distribution of lengths was recorded for the regions of complementary base sequence responsible for branch formation. It is proposed that most of the rings and branches are formed from classes of reiterated base sequence with an average length of 180 base pairs arranged intermittenly in HeLa-cell DNA. From the rate of formation of branched structures when HeLa-cell DNA segments were heat-denatured and annealed, it is estimated that the reiterated sequences are in families containing approximately 2400–24000 copies.
- Published
- 1974
14. Chemical linkage of the tail to the right-hand end of bacteriophage lambda DNA
- Author
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John O. Thomas
- Subjects
Formamide ,Lysis ,Nucleic Acid Denaturation ,Coliphages ,law.invention ,Bacteriophage ,chemistry.chemical_compound ,Endonuclease ,Structural Biology ,law ,Centrifugation, Density Gradient ,Escherichia coli ,Denaturation (biochemistry) ,Molecular Biology ,Carbodiimide ,Binding Sites ,Base Sequence ,Formamides ,biology ,DNA Viruses ,Endonucleases ,biology.organism_classification ,Molecular biology ,Carbodiimides ,Microscopy, Electron ,chemistry ,DNA, Viral ,biology.protein ,Biophysics ,Nucleic Acid Conformation ,Electron microscope ,Phosphorus Radioisotopes ,DNA - Abstract
When solutions of bacteriophage λ are treated with a water-soluble carbodiimide (CMC), then lysed with formamide and observed with the electron microscope, over 90% of the DNA molecules are found to be attached to phage heads and tails. Sedimentation analysis shows that lysis is complete, and denaturation mapping shows that the right-hand end † of the DNA, and never the left-hand end, is attached to the phage tails. When the carbodiimide-treated phage are lysed and the DNA cleaved with RI endonuclease, the shortest fragment, which contains the right end of λ DNA, is as expected the only fragment found attached to the tails. Comparison of the length of the tail-linked fragment with the length of the free DNA fragment shows that the DNA does not extend to the end of the tail. It does appear to intrude a short distance (30% of the length of the tail, or 130 DNA base-pairs), but this distance is just at the limit of resolution. When phage are placed in 80% formamide and then immediately spread for electron microscopy, about 10% of the phage have partially ejected DNA. Denaturation mapping shows that it is the right end of the DNA which is ejected first.
- Published
- 1974
15. Evidence for Somatic Generation of Antibody Diversity
- Author
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C. Steinberg, A. Bernardini, Susumu Tonegawa, and S. Dube
- Subjects
Immunoglobulins ,Biology ,Homology (biology) ,Cell Line ,Iodine Radioisotopes ,Immunoglobulin kappa-Chains ,Mice ,Nucleic acid thermodynamics ,chemistry.chemical_compound ,Animals ,Amino Acid Sequence ,RNA, Messenger ,Immunoglobulin Fragments ,Gene ,Mice, Inbred BALB C ,Messenger RNA ,Multidisciplinary ,Base Sequence ,Nucleic Acid Hybridization ,RNA ,Antibody Diversity ,DNA ,Genetic code ,Molecular biology ,Kinetics ,Genes ,chemistry ,Genetic Code ,Autoradiography ,Electrophoresis, Polyacrylamide Gel ,Female ,Biological Sciences: Genetics ,Plasmacytoma - Abstract
RNA preparations containing 70-80% mouse κ-chain mRNA have been prepared. The remainder consists of many RNA species, each of which represents a small fraction of the total RNA. The κ-chain mRNA preparation hybridizes with mouse liver DNA with bi-phasic kinetics, indicating that it consists of two fractions —“unique” and “reiterated.” Competition hybridization experiments show that the homology among the unique fractions from different mRNAs is the same as the homology among the amino acid sequences of the corresponding κ-chains. Hence, in addition to the C-region (constant-region) sequences, (most of) the V-region (variable-region) sequences are also derived from unique germ line genes. The reiterated fractions from different κ-chain mRNAs show essentially complete homology with each other. This fraction seems to consist mostly of sequences which do not code for amino-acid sequences of the secreted polypeptide chain, i.e., the “external” section of the mRNA molecule. It is concluded that the number of germ line genes is too small to account for the observed diversity of antibody molecules.
- Published
- 1974
16. Partial characterization of transfer RNA genes isolated from Neurospora crassa
- Author
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Ruben Ray and S. K. Dutta
- Subjects
Transfer DNA ,Hot Temperature ,Transcription, Genetic ,viruses ,Biology ,Nucleic Acid Denaturation ,Neurospora ,Neurospora crassa ,Nucleic acid thermodynamics ,chemistry.chemical_compound ,Drug Stability ,RNA, Transfer ,Species Specificity ,Centrifugation, Density Gradient ,Genetics ,Molecular Biology ,Chromatography ,Base Sequence ,fungi ,Crassa ,Nucleic Acid Hybridization ,DNA ,Ribosomal RNA ,biology.organism_classification ,Molecular biology ,Genes ,chemistry ,RNA, Ribosomal ,Mutation ,Transfer RNA ,Nucleic Acid Renaturation ,Hydroxyapatites ,Phosphorus Radioisotopes - Abstract
Purified DNA sequences that code for tRNA in Neurospora crassa were isolated and partially characterized. The tRNA cistrons comprise about 0.3 percent of the N. crassa genome. The tRNA:tDNA hybrids showed a buoyant density in cesium sulfate of 1.48 g cm-3 and sedimented in an intermediate position between native DNA and tRNA of N. crassa as expected. Te 50 of hybridized tRNA:tDNA molecules, reassociated tDNA: native DNA and homoduplexes of native DNA were 83.0°C, 88.5°C and 89.5°C respectively from thermal stability studies using hydroxyapatite chromatography. The isolated tRNA cistrons react almost completely with unlabeled DNA and tRNA of N. crassa or tRNA of the slime mutant of N. crassa; but react poorly with either ribosomal RNA or ribosomal RNA cistrons of N. crassa and tRNA of Escherichia coli. It appears that tRNA genes of N. crassa are repeated.
- Published
- 1973
17. The selective reaction of methoxyamine with cytidine residues in mammalian initiator transfer ribonucleic acid
- Author
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Peter W. Piper and Brian F.C. Clark
- Subjects
Molecular Sequence Data ,Codon, Initiator ,Sequence (biology) ,Cytidine ,Biology ,Hydroxylamines ,Mice ,chemistry.chemical_compound ,RNA, Transfer ,Methoxyamine ,Tumor Cells, Cultured ,Genetics ,Animals ,Molecule ,RNA, Neoplasm ,Binding site ,Binding Sites ,Base Sequence ,Uracil ,Articles ,chemistry ,Biochemistry ,Transfer RNA ,Nucleic Acid Conformation ,Multiple Myeloma ,Cytosine - Abstract
Methoxyamine reacts selectively with tRNA molecules at certain exposed cytosine residues usually located in non base-paired regions of the two dimensional clover leaf structure. Here methoxyamine is used for the first time in a study of a mammalian tRNA structure. One of the sequence abnormalities of myeloma initiator tRNA is a cytosine instead of the usual uracil immediately preceding the anticodon. A study of the reaction of the cytosine residues with methoxyamine indicates that the accessibility of bases to chemical reagents in the anticodon loop of this mammalian initiator tRNA is very similar to that observed for the bacterial initiator tRNA.
- Published
- 1974
18. Reiterated transfer RNA genes of Xenopus laevis
- Author
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Max L. Birnstiel, Stuart G. Clarkson, and Virginia Serra
- Subjects
Transfer DNA ,RNase P ,Xenopus ,Aminoacylation ,Haploidy ,Kidney ,Sulfur Radioisotopes ,Tritium ,Chromatography, DEAE-Cellulose ,Amino Acyl-tRNA Synthetases ,Methionine ,Ribonucleases ,RNA, Transfer ,Structural Biology ,Centrifugation, Density Gradient ,Animals ,Carbon Radioisotopes ,Molecular Biology ,Gene ,Cells, Cultured ,Nitrites ,Genetics ,Base Sequence ,biology ,Temperature ,Nucleic Acid Hybridization ,RNA ,Chromatography, Ion Exchange ,Genetic code ,biology.organism_classification ,Kinetics ,Genes ,Liver ,Transfer RNA ,Chromatography, Gel ,Spectrophotometry, Ultraviolet - Abstract
The proportion of the Xenopus laevis genome complementary to “7 S” RNA, unfractionated transfer RNA and some selected aminoacyl-tRNAs, and the sequence complexity of these RNA species, have been determined by following the kinetics of RNA-DNA hybridization on filters under conditions of RNA excess at optimum rate temperature. For hybridization of aminoacyl-labelled tRNAs, conditions for optimum aminoacylation were first determined and, where necessary, aminoacyl-tRNAs were treated with nitrous acid to prevent discharge during annealing. Neither the extent nor rate of hybridization was affected by this treatment. “7 S” RNA, coded for by 580 genes per haploid complement of chromosomes, reacts like a single family of nucleotide sequences, whereas about 43 basic tRNA sequences are coded for by at least 7800 genes. If hybrids are not treated with RNase A, the apparent tDNA redundancy is some 23% greater but no more nucleotide sequences are detectable. Taken together, the results suggest that each tRNA sequence is, on average, 200-fold reiterated. The reiteration varies, however, for different aminoacyl-tRNAs. Thus, hybridization resolves only one valyl-tRNA which is coded for by 240 genes, but at least four leucyl-tRNA sequences can be distinguished by hybridization, each of which is on average 90-fold reiterated. Reiteration also varies for the two methionyl-tRNAs detectable both by hybridization and by reversed phase chromatography: tRNA1Met and tRNA2Met are 310- and 170-fold reiterated, respectively, and each is kinetically homogeneous. These saturation values are almost exactly additive and are not influenced by the presence of other tRNA species. Thus the results suggest that Xenopus tRNAs are no more heterogeneous than would be predicted by the genetic code, despite the high but variable multiplicity of tRNA cistrons.
- Published
- 1973
19. Nonrepetitive DNA Sequence Representation in Sea Urchin Embryo Messenger RNA
- Author
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Robert B. Goldberg, Glenn A. Galau, Eric H. Davidson, and Roy J. Britten
- Subjects
Five-prime cap ,Embryo, Nonmammalian ,animal structures ,Transcription, Genetic ,Biology ,Tritium ,chemistry.chemical_compound ,Nucleic acid thermodynamics ,biology.animal ,Polysome ,Animals ,RNA, Messenger ,Uridine ,Biological Sciences: Cell Biology ,Sea urchin ,Messenger RNA ,Multidisciplinary ,Base Sequence ,Nucleic Acid Hybridization ,RNA ,DNA ,Ribosomal RNA ,Molecular biology ,Kinetics ,chemistry ,Polyribosomes ,Sea Urchins ,embryonic structures ,Phosphorus Radioisotopes ,Caltech Library Services - Abstract
Messenger RNA was prepared from developing sea urchin gastrulae by puromycin release from polyribosomes. Approximately 60% of the total mRNA radioactivity of the postnuclear supernatant was recovered and shown to be free of any other labeled RNA species such as ribosomal and nuclear RNA. The mRNA was examined by hybridization to DNA present in great excess. The mRNA hybridizes almost exclusively with nonrepetitive DNA. Almost all of the messenger RNA molecules of sea urchin gastrulae therefore consist of transcripts from nonrepetitive sequences. It appears that the structural genes expressed at this stage are typically not repeated in the genome and the mRNA does not include recognizable repetitive sequence.
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- 1973
20. The Organization of Highly Repeated DNA Sequences in Drosophila melanogaster Chromosomes
- Author
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R. Appels, D L Lindsley, E Goldring, Douglas L. Brutlag, William James Peacock, and C W Hinton
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Exonucleases ,Genotype ,Heterochromatin ,Cesium ,Biochemistry ,Chromosomes ,DNA sequencing ,chemistry.chemical_compound ,Centrifugation, Density Gradient ,Genetics ,medicine ,Animals ,Molecular Biology ,Cell Nucleus ,Base Sequence ,biology ,Nucleotides ,DNA ,Balancer chromosome ,biology.organism_classification ,Chromatin ,Microscopy, Electron ,Cell nucleus ,Drosophila melanogaster ,medicine.anatomical_structure ,chemistry ,Dactinomycin ,DNA, Circular - Published
- 1974
21. Absence of DNA-associated RNA in the fully repressed nucleus of chicken erythrocyte
- Author
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L.J. Rosenthal and Gerald M. Kolodny
- Subjects
Erythrocytes ,Biology ,Cell Fractionation ,Tritium ,chemistry.chemical_compound ,Genes, Regulator ,Centrifugation, Density Gradient ,medicine ,Animals ,Psychological repression ,Gene ,Cell Nucleus ,Base Sequence ,Nucleotides ,Nucleic Acid Hybridization ,RNA ,DNA ,Cell Biology ,Molecular biology ,Thin-layer chromatography ,In vitro ,medicine.anatomical_structure ,Biochemistry ,chemistry ,Autoradiography ,Chromatography, Thin Layer ,Chickens ,Nucleus - Abstract
DNA from fully repressed chicken erythrocyte nuclei was examined for stably associated RNA which could possibly serve a role in genetic repression. Alkaline hydrolysates of DNA purified on cesium chloride gradients showed an absence of sufficient ribonucleotides, in stable association with DNA, on both thin layer chromatography and by in vitro tritium labeling to serve to localize or identify all the deoxynucleotide gene sequences in the fully repressed chicken erythrocyte nucleus.
- Published
- 1974
22. Transcription of Saccharomyces cerevisiae Ribosomal DNA In Vivo and In Vitro
- Author
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Harlyn O. Halvorson, Robert H. Rownd, Jesus Sebastian, and Jane Harris Cramer
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Guanine ,Transcription, Genetic ,DNA polymerase ,DNA polymerase II ,Saccharomyces cerevisiae ,Tritium ,Cytosine ,Transcription (biology) ,Centrifugation, Density Gradient ,RNA polymerase I ,RNA, Messenger ,Polymerase ,Transcription bubble ,Multidisciplinary ,DNA clamp ,Base Sequence ,biology ,Nucleic Acid Hybridization ,DNA ,DNA-Directed RNA Polymerases ,Templates, Genetic ,Molecular biology ,Molecular Weight ,Biochemistry ,Genetic Code ,RNA, Ribosomal ,Coding strand ,biology.protein ,Biological Sciences: Biochemistry ,Phosphorus Radioisotopes - Abstract
In vivo , ribosomal RNA of Saccharomyces cerevisiae is transcribed from the light strand of γ DNA. In vitro , γ DNA is transcribed with equal efficiency by both of the yeast nuclear RNA polymerases, polymerase I and polymerase II; however the RNA products synthesized by the two enzymes differ from each other both in size and in the relative composition of guanine and cytosine. RNA synthesized by polymerase I hybridizes preferentially to the light strand, while that synthesized by polymerase II hybridizes equally well to either strand. Selective transcription of the light strand of the ribosomal DNA also occurs when high-molecular-weight total nuclear DNA is used as template.
- Published
- 1974
23. Immunoglobulin Genes: Arranged in Tandem or in Parallel?
- Author
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O. Smithies
- Subjects
DNA Replication ,Genetic Linkage ,Immunoglobulins ,Biochemistry ,Immunoglobulin G ,Antibody Specificity ,Immunogenetics ,Genetics ,Humans ,Base sequence ,Amino Acid Sequence ,Immunoglobulin Fragments ,Molecular Biology ,Peptide sequence ,Gene ,Cell Nucleus ,Chromosome Aberrations ,Recombination, Genetic ,Base Sequence ,Tandem ,biology ,Immunoglobulin genes ,Chromosome Mapping ,DNA ,Molecular biology ,Genes ,Models, Chemical ,biology.protein ,Antibody - Published
- 1974
24. A FINE STRUCTURE MAP OF THE SALMONELLA HISTIDINE OPERATOR-PROMOTER
- Author
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Philip Hartman, Bert Ely, and David B. Fankhauser
- Subjects
Salmonella typhimurium ,Operator (biology) ,Operon ,Base pair ,Polynucleotides ,Investigations ,Biology ,medicine.disease_cause ,Models, Biological ,Genes, Regulator ,Genetics ,medicine ,Histidine ,Gene ,Recombination, Genetic ,Mutation ,Base Sequence ,Chromosome Mapping ,Chromosomes, Bacterial ,Phenotype ,Molecular biology ,Genes ,Recombination - Abstract
Over 100 regulatory mutations linked to the histidine (his) operon of S. typhimurium have been isolated. They all map in a region estimated to be several hundred base pairs in length located at one end of the his operon ("the hisO region"). The mutations are located at sixteen recombinationally separable sites or are deletions encompassing several sites. Data obtained from pairs of reciprocal three-point tests show that "constitutive" (high enzyme levels) and "promoter-like" (low enzyme levels) hisO mutations are interspersed on the genetic map. In a few crosses, recombination was not observed to occur between markers shown to occupy different sites based on behavior in other recombination tests.
- Published
- 1974
25. Phosphorylation of DNA-binding Nuclear Acidic Proteins and Gene Activation in the HeLa Cell Cycle
- Author
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Jonathan Karn, Edward M. Johnson, Vincent G. Allfrey, Akira Inoue, and G. Vidali
- Subjects
Thymus Gland ,Methylation ,Biochemistry ,Chromatography, Affinity ,Phosphates ,Histones ,HeLa ,chemistry.chemical_compound ,Genetics ,Animals ,Humans ,Molecular Biology ,Regulation of gene expression ,Base Sequence ,biology ,DNA ,Templates, Genetic ,Cell cycle ,Phosphoproteins ,biology.organism_classification ,Cell biology ,Nucleoproteins ,Genes ,chemistry ,Phosphorylation ,Cattle ,Electrophoresis, Polyacrylamide Gel ,Enzyme Repression ,Phosphorus Radioisotopes ,Cell Division ,HeLa Cells ,Protein Binding - Published
- 1974
26. FRAMESHIFT MUTATIONS
- Author
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J R, Roth
- Subjects
DNA Replication ,Salmonella typhimurium ,Alkylating Agents ,Base Sequence ,Transcription, Genetic ,Hemoglobins, Abnormal ,DNA Viruses ,Coliphages ,Saccharomyces ,Models, Chemical ,Genetic Code ,Heterocyclic Compounds ,Neoplasms ,DNA, Viral ,Mutation ,Escherichia coli ,Genetics ,Acridines ,Humans ,Muramidase ,Mutagens - Published
- 1974
27. Synthesis of Viral-Specific RNA in Cells Infected with the Parvovirus, Kilham Rat Virus
- Author
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Bruce Redler and Lois Ann Salzman
- Subjects
Time Factors ,Genotype ,viruses ,Immunology ,RNA-dependent RNA polymerase ,In Vitro Techniques ,Virus Replication ,Wilms Tumor ,Microbiology ,Parvoviridae ,Virus ,Cell Line ,chemistry.chemical_compound ,Transcription (biology) ,Virology ,Animal Viruses ,Animals ,Base Sequence ,DNA synthesis ,biology ,Parvovirus ,Nucleic Acid Hybridization ,RNA ,DNA, Neoplasm ,biology.organism_classification ,Molecular biology ,Centrifugation, Zonal ,Rats ,Molecular Weight ,chemistry ,Cell culture ,Insect Science ,DNA, Viral ,RNA, Viral ,Phosphorus Radioisotopes ,DNA - Abstract
We have studied the viral-specific RNA synthesized after infection of a permissive cell line with Kilham rat virus (KRV). The RNA was shown to be virus specific by analysis of its nucleotide base ratios and by hybridization with KRV and cellular DNA. Viral RNA is synthesized as early as 2 h after infection. This viral RNA synthesis occurs before viral progeny DNA synthesis which is initiated at 7 to 8 h after infection. The predominant viral RNA synthesized before and after viral progeny DNA synthesis has a sedimentation coefficient of approximately 18 S in dimethylsulfoxide-sucrose gradients and a calculated molecular weight of 6.5 × 10 5 to 7.5 × 10 5 . KRV contains a molecule of single-stranded DNA with a molecular weight of approximately 1.6 × 10 6 . If the viral-specific 18 S RNA is a homogenous species, it would account for 40 to 50% of the viral genome. A small amount of 26 S viral RNA with a molecular weight of 1.6 × 10 6 to 1.7 × 10 6 can also be detected. If this 26 S RNA is a single viral-specific entity, it could represent a transcription of the entire KRV genome.
- Published
- 1974
28. Evidence for common nucleotide sequences in the RNA subunits comprising Rous sarcoma virus 70 S RNA
- Author
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R.E. Smith, Kristina Quade, and J. L. Nichols
- Subjects
Oligonucleotides ,RNA-dependent RNA polymerase ,Biology ,Chromatography, DEAE-Cellulose ,Ribonucleases ,Virology ,Nucleotide ,Ribonuclease ,chemistry.chemical_classification ,Rous sarcoma virus ,Base Sequence ,Nucleotides ,Oligonucleotide ,RNA ,biology.organism_classification ,Molecular biology ,Molecular Weight ,Avian Sarcoma Viruses ,chemistry ,Polynucleotide ,RNA editing ,biology.protein ,Autoradiography ,RNA, Viral ,Electrophoresis, Polyacrylamide Gel ,Phosphorus Radioisotopes - Abstract
Digestion of Rous sarcoma virus 32 P-labeled high molecular-weight RNA with T 1 ribonuclease resulted in the release of approximately 30 unique large oligonucleotides which were resolved by electrophoresis and chromatography on thin layers of cellulose and DEAE-cellulose. Determination of the radioactivity present in each oligonucleotide of known chain length and in the remaining digestion products made it possible to estimate the total number of residues expected in a polynucleotide chain containing the sequences represented. The oligonucleotides are present in amounts greater than would be expected for a unique and nonrepetitive 70 S RNA molecule with a molecular weight of 1 × 10 7 . Many of the sequences must, therefore, be present in more than one of the 35 S RNA subunits comprising the 70 S RNA.
- Published
- 1974
29. Comparison of large fragments obtained by T1 RNase digestion of ribosomal and nucleolar preribosomal RNA of novikoff hepatoma ascites cells: The 5′-terminal eicosanucleotide
- Author
-
Yong C. Choi and Harris Busch
- Subjects
Carcinoma, Hepatocellular ,RNase P ,Biophysics ,Biology ,Biochemistry ,Chromatography, DEAE-Cellulose ,18S ribosomal RNA ,Ribonucleases ,28S ribosomal RNA ,Preribosomal RNA ,Electrophoresis, Paper ,Pancreas ,Molecular Biology ,Base Sequence ,Oligonucleotide ,Liver Neoplasms ,RNA ,Neoplasms, Experimental ,Cell Biology ,Ribonucleotides ,Ribosomal RNA ,Chromatography, Ion Exchange ,Molecular biology ,Liver ,RNA, Ribosomal ,Digestion ,Phosphorus Radioisotopes ,Cell Nucleolus - Abstract
Summary Large T 1 RNase fragments of 18S and 28S rRNA and their nucleolar precursors were separated by successive elution from columns of DEAE Sephadex at pH 7.6 and DEAE-cellulose at pH 3.4, respectively. The fragments that contain the methylated oligonucleotides Am-Gm-Cm-Ap, Um-Gm-Up, Gm-Up and Cm-Ap are referred to as α2 −2 , α2 −4 , α2 −3 and α1 −1 ′. Fragment α2 −2 is the eicosanucleotide Am-Gm-Cm-A-A-A-U-U-C-A-U-A-U-U-C-A-A-A-C-Gp which is the 5′ end of 28S rRNA and its precursors including nucleolar 45S RNA. The dinucleotide Cm-Ap is present only in 18S rRNA and 45S nucleolar RNA.
- Published
- 1974
30. Mutant tyrosine transfer ribonucleic acids of Escherichia coli: Construction by recombination of a double mutant A1G82 chargeable with glutamine
- Author
-
J.D. Smith, J. E. Celis, and H. Inokuchi
- Subjects
Electrophoresis ,Glutamine ,Mutant ,Biology ,medicine.disease_cause ,law.invention ,Suppression, Genetic ,RNA, Transfer ,Transduction, Genetic ,Structural Biology ,law ,Escherichia coli ,medicine ,Tyrosine ,Molecular Biology ,Gene ,Crosses, Genetic ,Recombination, Genetic ,Mutation ,Base Sequence ,Chromosome Mapping ,Chromosomes, Bacterial ,Molecular biology ,RNA, Bacterial ,Biochemistry ,bacteria ,Suppressor ,Phosphorus Radioisotopes ,Recombination - Abstract
A double mutant A1G82 of the su III + tyrosine gene in Escherichia coli was constructed by genetic cross. This mutant is a stronger glutamine-inserting amber suppressor than either of the single mutants A1 or G82.
- Published
- 1974
31. Discriminatory Ribosome Rebinding of Isolated Regions of Protein Synthesis Initiation from the Ribonucleic Acid of Bacteriophage R17
- Author
-
Joan A. Steitz
- Subjects
5.8S ribosomal RNA ,Oligonucleotides ,RNA-dependent RNA polymerase ,Bacillus ,Biology ,Coliphages ,Ribosome ,Viral Proteins ,Ribonucleases ,Escherichia coli ,RNA, Messenger ,Peptide Chain Initiation, Translational ,Messenger RNA ,Binding Sites ,Multidisciplinary ,Base Sequence ,Hydrolysis ,RNA ,Internal ribosome entry site ,A-site ,Biochemistry ,Nucleic Acid Conformation ,RNA, Viral ,Biological Sciences: Biochemistry ,Eukaryotic Ribosome ,Ribosomes - Abstract
To determine whether bacterial ribosomes recognize a distinguishing feature in the immediate vicinity of actual initiator codons or are directed to these sites through involvement of other portion(s) of the mRNA molecule, the interaction between ribosomes and defined 32 P-labeled initiator fragments from R17 RNA was studied. When incubated with mixtures of the three sites, ribosomes from Bacillus stearothermophilus (which initiate only the A protein on intact phage RNA) are able to select out the A fragment and discriminate against the coat and replicase initiator regions. By contrast, Escherichia coli ribosomes do not rebind that coat-protein region of R17 most efficiently, as they in the native RNA, but likewise prefer the A-protein initiator fragment. In both cases, ribosome binding of the isolated A site is comparable by several criteria to normal polypeptide-chain initiation on an intact R17 messenger RNA in vitro . E. coli ribosomal preference for the A site is confirmed in experiments with randomly fragmented R17 RNA, by both the initiation dipeptide and ribosome protection assay. Thus the A-protein ribosome-binding site of R17 RNA appears intrinsically to be a good initiator, while efficient recognition of the coat and replicase regions requires the participation of some portion of the remainder of the phage RNA molecule.
- Published
- 1973
32. A Sequence of 83 Nucleotides Containing the Replicase Cistron Ribosome Binding Site of Phage Qbeta RNA
- Author
-
Martin A. Billeter, Alan G. Porter, and J. Hindley
- Subjects
Receptors, Drug ,viruses ,Oligonucleotides ,RNA-dependent RNA polymerase ,Biology ,Virus Replication ,Coliphages ,Biochemistry ,Ribosome ,Ribonucleases ,Cistron ,Escherichia coli ,Nucleotide ,Pancreas ,chemistry.chemical_classification ,Gel electrophoresis ,Base Sequence ,RNA ,Hydrogen-Ion Concentration ,Iontophoresis ,Ribonucleotides ,Genetic code ,Molecular biology ,Ribosomal binding site ,chemistry ,Genetic Code ,Autoradiography ,RNA, Viral ,Electrophoresis, Polyacrylamide Gel ,Phosphorus Radioisotopes ,Ribosomes - Abstract
70-S initiation complexes of Escherichia coli ribosomes and 32P-labelled Qβ RNA were digested with T1 ribonuclease at 0°C, and the ribosome-protected Qβ initiator fragments resolved by poly-acrylamide gel electrophoresis. The sequence of one of the fragments (83 nucleotides long) has been determined. It begins with the sequence of 32 nucleotides already determined for the ribosome binding site of the replicase cistron. The sequence of the remaining 51 nucleotides establishes the order of a further 17 amino acids in the phage-coded replicase subunit. Seven out of the first 11 amino acids in the replicase subunits of phages MS2 and Qβ are identical.
- Published
- 1974
33. Polyadenylate Sequences and Biologic Activity of Human Globin Messenger Ribonucleic Acid
- Author
-
Arthur Bank, Roberto Gambino, Judy Banks, and Almira Cann
- Subjects
Poly U ,Messenger ribonucleic acid ,Five-prime cap ,Hot Temperature ,Reticulocytes ,Anemia, Sickle Cell ,Biology ,Nucleic Acid Denaturation ,Tritium ,Biochemistry ,Chromatography, Affinity ,Reticulocyte ,Complementary DNA ,Centrifugation, Density Gradient ,medicine ,Humans ,Polyadenylate ,RNA, Messenger ,Globin ,Molecular Biology ,Polyadenylic acid ,Messenger RNA ,Base Sequence ,Adenine Nucleotides ,Temperature ,Nucleic Acid Hybridization ,Cell Biology ,Chromatography, Ion Exchange ,Molecular biology ,Globins ,Kinetics ,medicine.anatomical_structure ,Protein Biosynthesis ,Spectrophotometry, Ultraviolet ,Hydroxyapatites - Abstract
The relationship of biologic activity and polyadenylic acid (poly(A)) content of human reticulocyte messenger RNA has been investigated. Purified 6 to 16 S RNA was fractionated on an oligodeoxythymidylate-cellulose column and assayed for (a) messenger RNA content by hybridization to [3H]CTP-labeled complementary DNA, (b) biologic activity in a Krebs ascites cell-free system, and (c) poly(A) content by hybridization to [3H]polyuridylate. The results indicate that biologic activity of human reticulocyte messenger RNA is independent of its poly(A) length and proportional to its messenger RNA content.
- Published
- 1974
34. Effect mutagèné de l'acide nalidixique sur le bactériophage T4
- Author
-
P.R.R. Vigier
- Subjects
endocrine system ,Nalidixic acid ,medicine.drug_class ,Base pair ,Health, Toxicology and Mutagenesis ,fungi ,Antibiotics ,Reversion ,food and beverages ,Bacterial host ,Biology ,Microbiology ,Genotype ,Genetics ,medicine ,Base sequence ,Molecular Biology ,medicine.drug - Abstract
Nalidixic acid can efficiently induce the reversion of some T4 rII mutations. The great majority of the strains whose reversion can be induced by this antibiotic are also sensitive to the mutagenic action of proflavin, indicating that mutagenicity of nalidixic acid results in base pair addition or deletion. With bacterial host strains resistant to nalidixic acid, the mutagenic effect is greatly reduced but not the effects on phage multiplication. This fact shows that the mutagenic agent is not the nalidixic acid itself but a derivative synthesized in sensitive bacterial strains.
- Published
- 1974
35. Amplified Ribosomal DNA from Xenopus laevis Has Heterogeneous Spacer Lengths
- Author
-
Igor B. Dawid, A. Deutch, Peter K. Wellauer, T. Higashinakagawa, Dana Carroll, Ronald H. Reeder, and Donald D. Brown
- Subjects
Multidisciplinary ,Base Sequence ,biology ,Xenopus ,DNA ,Electrophoresis, Disc ,Endonucleases ,biology.organism_classification ,Molecular biology ,Ribosome ,18S ribosomal RNA ,Microscopy, Electron ,chemistry.chemical_compound ,Restriction enzyme ,Genes ,chemistry ,28S ribosomal RNA ,Animals ,Biological Sciences: Biochemistry ,Nucleolus organizer region ,Ribosomes ,Ribosomal DNA - Abstract
Eco R 1 restriction endonuclease makes two cuts in each repeating unit of amplified ribosomal DNA (rDNA) from Xenopus laevis . The locations of these cuts have been established by comparison of the secondary structure of single-stranded Eco R 1 fragments (as visualized in the electron microscope) with that of X. laevis rRNAs and of long strands of uncut rDNA. Of the two classes of fragments generated, the smaller one contains 90% of the 28S rRNA gene, has a duplex molecular weight of 3.0 × 10 6 and is homogeneous in size. The larger class of molecules contains 80% of the 18S rRNA gene and all of the nontranscribed spacer. These latter fragments are heterogeneous with molecular weights ranging from 4.0 to 5.9 × 10 6 . The distribution of sizes within the large class of fragments varies among different preparations of rDNA, and heterogeneity is present in the DNA amplified from the rDNA of a single nucleolar organizer. The heterogeneity is located in the nontranscribed spacer region which is variable in length. This has been demonstrated by the formation of deletion loops in heteroduplexes made between larger fragments of different lengths.
- Published
- 1974
36. A biochemical comparison of the related bacteriophages T7, φI, φII, W31, H, and T3
- Author
-
Richard W. Hyman, Ilze Brunovskis, and William C. Summers
- Subjects
Salmonella typhimurium ,S-Adenosylmethionine ,Time Factors ,Hydrolases ,Polyacrylamide ,Shigella sonnei ,Biology ,Bioinformatics ,Coliphages ,law.invention ,Viral Proteins ,chemistry.chemical_compound ,law ,Virology ,Escherichia coli ,Carbon Radioisotopes ,RNA, Messenger ,Amino Acids ,Base Sequence ,RNA ,Biological Evolution ,Electrophoreses ,Microscopy, Electron ,Genes ,Biochemistry ,chemistry ,DNA, Viral ,RNA, Viral ,Electrophoresis, Polyacrylamide Gel ,Chromatography, Thin Layer ,Electron microscope ,DNA - Abstract
The female-specific coliphages T7, T3, φI, φII, W31, and phage H have been compared by several biochemical techniques. The DNA base-sequence homologies have been determined by examining the appropriate heteroduplexes in the electron microscope. The patterns of RNA and protein syntheses have been investigated by electrophoreses of the radioactively labeled material on polyacrylamide gels. Phages φI, φII, W31, and H are clearly closely related to T7 and more distantly related to T3.
- Published
- 1974
37. Terminal Cross-linking of DNA Catalyzed by an Enzyme System Containing DNA Ligase, DNA Polymerase, and Exonuclease of Bacteriophage T7
- Author
-
Paul D. Sadowski, Allison McGeer, and Andrew Becker
- Subjects
DNA Replication ,Exonucleases ,DNA polymerase ,DNA polymerase II ,Tritium ,Coliphages ,Chromatography, DEAE-Cellulose ,Species Specificity ,Centrifugation, Density Gradient ,Escherichia coli ,Ultrasonics ,Carbon Radioisotopes ,Klenow fragment ,chemistry.chemical_classification ,DNA ligase ,DNA clamp ,Base Sequence ,biology ,T7 DNA polymerase ,General Medicine ,Chromatography, Ion Exchange ,Molecular biology ,Polynucleotide Ligases ,Genes ,chemistry ,Biochemistry ,DNA Nucleotidyltransferases ,DNA, Viral ,Mutation ,biology.protein ,Nucleic Acid Conformation ,Spectrophotometry, Ultraviolet ,DNA polymerase I ,Thymine ,In vitro recombination ,Thymidine - Abstract
An enzymatic activity that terminally cross-links T7 DNA has been detected in extracts from phage T7-infected Escherichia coli cells. This activity required the functional products of gene 1.3 (T7 DNA ligase), gene 5 (T7 DNA polymerase), and gene 6 (T7 exonuclease) as well as Mg2+ ions, the four deoxytriphosphates, and ATP. The cross-linking system could be reconstituted with purified ligase, polymerase, and exonuclease, and maximal activity required the presence of all three enzymes. The system was active on phage DNA which possessed unique termini but not on DNA with non-unique ends.
- Published
- 1974
38. Transcription of Polydeoxythymidylate Sequences in the Genome of the Cellular Slime Mold, Dictyostelium discoideum
- Author
-
Richard A. Firtel, Harvey F. Lodish, and Allan Jacobson
- Subjects
Chemical Phenomena ,Transcription, Genetic ,Polynucleotides ,Cesium ,Tritium ,Dictyostelium discoideum ,Nucleic acid thermodynamics ,Polysaccharides ,Transcription (biology) ,Centrifugation, Density Gradient ,Slime mold ,Thymine Nucleotides ,Myxomycetes ,Nucleotide ,RNA, Messenger ,Biological Sciences: Cell Biology ,chemistry.chemical_classification ,Chromatography ,Messenger RNA ,Multidisciplinary ,Base Sequence ,biology ,Nucleotides ,Sulfates ,Nucleic Acid Hybridization ,Iontophoresis ,biology.organism_classification ,Dictyostelium ,Chemistry ,Biochemistry ,chemistry ,Genetic Code ,Polynucleotide ,Electrophoresis, Polyacrylamide Gel ,Phosphorus Radioisotopes - Abstract
Messenger RNA of the cellular slime mold, Dictyostelium discoideum , contains about equimolar amounts of two classes of poly(adenylic acid) [poly(A)]; one is about 25 nucleotides long and the second about 100 nucleotides long. At least half of the messenger RNA molecules contain one sequence each of poly(A) 25 and poly(A) 100 ; both poly(A) sequences are located near the 3′ end of messenger RNA, and the kinetics of their appearance on messenger RNA precursor indicates that poly(A) 25 is added before poly(A) 100 . Dictyostelium nuclear DNA contains 14,000-15,000 sequences of poly(dT) 25 which could code for the smaller poly(A) residues. The poly(A) 100 must be added post-transcriptionally. The poly(dT) 25 sequences are interspersed throughout the genome and may well represent transcription termination regions.
- Published
- 1974
39. Base composition heterogeneity in kinetoplast DNA from four species of hemoflagellates
- Author
-
Maurice Steinert and Suzanne Van Assel
- Subjects
Trypanosoma ,Hot Temperature ,Deoxyribonucleotides ,Trypanosoma brucei brucei ,Biophysics ,Biology ,Nucleic Acid Denaturation ,Biochemistry ,High Resolution Melt ,chemistry.chemical_compound ,Species Specificity ,parasitic diseases ,Animals ,Base sequence ,Base (exponentiation) ,Molecular Biology ,Genetics ,Eukaryota ,DNA ,Cell Biology ,Biological evolution ,Biological Evolution ,chemistry ,Evolutionary biology ,Kinetoplast ,Composition (visual arts) ,DNA, Circular - Abstract
Summary Evidence for intramolecular base composition heterogeneity in kinetoplast DNA has been found by high resolution melting analysis. The specific melting profiles, obtained for the kinetoplast DNA isolated from four different species, indicate that extensive variations in base sequence occurred in this DNA during evolution of the trypanosomatidae.
- Published
- 1974
40. Possibilities for the Evolution of the Genetic Code from a Preceding Form
- Author
-
Thomas H. Jukes
- Subjects
Uracil Nucleotides ,Reading frame ,Saccharomyces cerevisiae ,Cytosine Nucleotides ,Biology ,Models, Biological ,RNA, Transfer ,Escherichia coli ,Amino Acid Sequence ,RNA, Messenger ,Amino Acids ,Inosine Nucleotides ,Expanded genetic code ,Genetics ,chemistry.chemical_classification ,Multidisciplinary ,Xenobiology ,Base Sequence ,Adenine Nucleotides ,Nucleotides ,Nucleosides ,Translation (biology) ,Genetic code ,Biological Evolution ,Guanine Nucleotides ,Amino acid ,chemistry ,Genetic Code ,Protein Biosynthesis ,Codon usage bias ,Transfer RNA - Abstract
Analysis of the interaction between mRNA codons and tRNA anticodons suggests a model for the evolution of the genetic code. Modification of the nucleic acid following the anticodon is at present essential in both eukaryotes and prokaryotes to ensure fidelity of translation of codons starting with A, and the amino acids which could be coded for before the evolution of the modifying enzymes can be deduced.
- Published
- 1973
41. The determination of RNA homogeneity by molecular hybridization
- Author
-
John O. Bishop and George P. Smith
- Subjects
Genetics ,Messenger RNA ,Erythrocytes ,Base Sequence ,Homogeneity (statistics) ,Nucleic Acid Hybridization ,RNA ,DNA ,Computational biology ,Fibroblasts ,Biology ,Models, Biological ,General Biochemistry, Genetics and Molecular Biology ,Molecular hybridization ,Ducks ,RNA, Ribosomal ,Animals ,Nucleic Acid Conformation ,RNA, Messenger - Abstract
A method is described which allows estimates to be made of the purity or identity of preparations of purified mRNA species.
- Published
- 1974
42. Nucleotide clusters in deoxyribonucleic acids. IX. Pyrimidine oligonucleotides of mouse L-cell satellite deoxyribonucleic acid and main-band deoxyribonucleic acid
- Author
-
Klaus Harbers and John H. Spencer
- Subjects
Chemical Phenomena ,Pyrimidine ,Cell ,Oligonucleotides ,DNA, Single-Stranded ,Thymus Gland ,Cytosine Nucleotides ,Biochemistry ,Chromatography, DEAE-Cellulose ,Mice ,chemistry.chemical_compound ,L Cells ,medicine ,Animals ,Thymine Nucleotides ,Nucleotide ,Cell Nucleus ,chemistry.chemical_classification ,Base Sequence ,DNA synthesis ,biology ,Oligonucleotide ,DNA ,biology.organism_classification ,Chemistry ,Microscopy, Electron ,medicine.anatomical_structure ,chemistry ,Cattle ,Pyrimidine Nucleotides ,Satellite (biology) ,Ultracentrifuge ,Phosphorus Radioisotopes ,Ultracentrifugation - Published
- 1974
43. A catalogue of the pyrimidine oligodeoxyribonucleotides found in bacteriophage f1 DNA
- Author
-
George B. Petersen and W.P. Tate
- Subjects
Purine ,Pyrimidine ,Deoxyribonucleotides ,Oligonucleotides ,Cytosine Nucleotides ,Biology ,Nucleic Acid Denaturation ,Coliphages ,Chromatography, DEAE-Cellulose ,chemistry.chemical_compound ,Virology ,Centrifugation, Density Gradient ,Escherichia coli ,Thymine Nucleotides ,Nucleotide ,chemistry.chemical_classification ,Aniline Compounds ,Base Sequence ,Nucleic Acid Strand ,Thymine ,chemistry ,Biochemistry ,Spectrophotometry ,DNA, Viral ,Phosphorus Radioisotopes ,Cytosine ,DNA - Abstract
Pyrimidine oligodeoxyribonucleotides, comprising those sequences of pyrimidine nucleotides that are flanked by a purine nucleotide at each end in the original nucleic acid strand, were released from f1 DNA by the action of diphenylamine in acid solution and separated by ion exchange chromatography. Improvements of earlier analytical techniques have permitted the assembly of a complete catalog of frequencies of occurrence of these sequences. All possible components of different base composition up to chain length 4 were detected, but some of the possible cytosine-rich sequences are missing from the groups of chain lengths 5–8. No sequence of consecutive thymine deoxyribonucleotides of chain length greater than 5 was detected. Ten sequences of chain lengths ranging from 6 to 19 were found to occur only once in each DNA molecule, the last representing the longest sequence of consecutive pyrimidine deoxyribonucleotides yet found in DNA of any origin. The unique sequences of chain lengths 13 and 19 are rich in cytosine and would not be expected to occur at all in a randomly arranged polymer with the base composition of this DNA.
- Published
- 1974
44. Sites of methylation of purified transfer ribonucleic acid preparations by enzymes from normal tissues and from tumours induced by dimethylnitrosamine and 1,2-dimethylhydrazine
- Author
-
Anthony E. Pegg
- Subjects
Nitrosamines ,Colon ,Guanosine ,Saccharomyces cerevisiae ,Biology ,Kidney ,Biochemistry ,Chromatography, DEAE-Cellulose ,Mice ,chemistry.chemical_compound ,Ribonucleases ,RNA, Transfer ,Species Specificity ,Nucleic Acids ,Escherichia coli ,Animals ,Carbon Radioisotopes ,Molecular Biology ,chemistry.chemical_classification ,tRNA Methyltransferases ,Base Sequence ,RNA ,Cytidine ,Neoplasms, Experimental ,Cell Biology ,Methylation ,Molecular biology ,Kidney Neoplasms ,Rats ,TRNA Methyltransferases ,RNA, Bacterial ,Hydrazines ,Enzyme ,chemistry ,Organ Specificity ,Colonic Neoplasms ,Transfer RNA ,Nucleoside - Abstract
1. The sites within the tRNA sequence of nucleosides methylated by the action of enzymes from mouse colon, rat kidney and tumours of these tissues acting on tRNA(Asp) from yeast and on tRNA(Glu) (2), tRNA(fMet) and tRNA(Val) (1) from Escherichia coli were determined. 2. The same sites in a particular tRNA were methylated by all of these extracts. Thus tRNA(Glu) (2) was methylated at the cytidine residue at position 48 and the adenosine residue at position 58 from the 5'-end of the molecule; tRNA(Asp) was methylated at the guanosine residue at position 26 from the 5'-end of the molecule; tRNA(fMet) was methylated at the guanosine residues 9 and 27, the cytidine residue 49 and the adenosine residue 59 from the 5'-end; tRNA(Val) (1) was methylated at the guanosine residue 10, the cytidine residue 48 and the adenosine residue 58 from the 5'-end. 3. All of these sites within the clover leaf structure of the tRNA sequence are occupied by a methylated nucleoside in some tRNA species of known sequence. It is concluded that methylation of tRNA from micro-organisms by enzymes from mammalian tissues in vitro probably does accurately represent the specificity of these enzymes in vivo. However, there was no evidence that the tumour extracts, which had considerably greater tRNA methylase activity than the normal tissues, had methylases with altered specificity capable of methylating sites not methylated in the normal tissues.
- Published
- 1974
45. Evidence for non-repetitive subunits in the genome of rous sarcoma virus
- Author
-
Habold E. Vabmus, J. Michael Bishop, Warben E. Levinson, A. J. Faras, and John M. Taylor
- Subjects
Rous sarcoma virus ,Base Sequence ,Genotype ,viruses ,Poliovirus ,Nucleic acid sequence ,Nucleic Acid Hybridization ,RNA ,Biology ,Tritium ,medicine.disease_cause ,biology.organism_classification ,Virology ,Genome ,Virus ,Molecular hybridization ,Molecular Weight ,Avian Sarcoma Viruses ,Rs virus ,Structural Biology ,DNA, Viral ,medicine ,RNA, Viral ,Molecular Biology - Abstract
The complexity of Rous sarcoma virus RNA has been determined using molecular hybridization. Relative to poliovirus RNA, the complexity of Rous sarcoma virus is 9·3 × 10 6 daltons, a value close to its physically-determined molecular weight of about 10 7 . Our interpretation is that the 35 S RNA subunits of the 70 S virus genome are non-repetitive, that is, each possesses a unique nucleotide sequence, although a limited amount of redundancy cannot be excluded.
- Published
- 1974
46. Theoretical models for heterogeneity of base composition in DNA
- Author
-
R.A. Elton
- Subjects
DNA, Bacterial ,Statistics and Probability ,Guanine ,Genotype ,Theoretical models ,Biology ,General Biochemistry, Genetics and Molecular Biology ,Cytosine ,chemistry.chemical_compound ,Bacterial Proteins ,Molecular size ,Centrifugation, Density Gradient ,Escherichia coli ,Amino Acid Sequence ,Base (exponentiation) ,Gene ,Probability ,Sequence (medicine) ,Genetics ,Base Sequence ,General Immunology and Microbiology ,Applied Mathematics ,DNA ,General Medicine ,Composition (combinatorics) ,C content ,Models, Structural ,Streptococcus pneumoniae ,chemistry ,Genetic Code ,Evolutionary biology ,Modeling and Simulation ,Nucleic Acid Conformation ,General Agricultural and Biological Sciences ,Bacillus subtilis - Abstract
Data on DNA base composition heterogeneity and molecular size, mainly from bacteria, are compiled from the literature. A series of theoretical models of increasing complexity is put forward, and it is concluded that the data support a model in which the DNA consists of a sequence of “segments” with different underlying base compositions. Estimates of mean segment length and variance of G + C content are made. The possibility that the excess heterogeneity above random results from variation in the composition of coded proteins is considered and rejected. It is concluded that the heterogeneity is probably caused by variations in the relative use of synonymous codons in different genes.
- Published
- 1974
47. Physical identity of the SV40 deoxyribonucleic acid sequence recognized by the Eco RI restriction endonuclease and modification methylase
- Author
-
Achilles Dugaiczyk, Howard M. Goodman, Herbert W. Boyer, and Joe Hedgpeth
- Subjects
S-Adenosylmethionine ,Modification methylase ,Chromatography, Paper ,Fluoroacetates ,Polynucleotides ,Oligonucleotides ,EcoRI ,Simian virus 40 ,Tritium ,Methylation ,Biochemistry ,Structure-Activity Relationship ,chemistry.chemical_compound ,Electrophoresis, Paper ,Sequence (medicine) ,Genetics ,Binding Sites ,Deoxyribonucleases ,Base Sequence ,biology ,Nucleotides ,Phosphotransferases ,DNA ,Methyltransferases ,Physical identity ,Endonucleases ,Adenosine Monophosphate ,Polynucleotide Ligases ,Restriction enzyme ,chemistry ,DNA, Viral ,biology.protein ,Phosphorus Radioisotopes - Published
- 1974
48. Cytological differentiation of constitutive heterochromatin
- Author
-
Clark Rw, Pathak, Jalal Sm, and T. C. Hsu
- Subjects
Male ,medicine.medical_specialty ,Satellite DNA ,Heterochromatin ,Biology ,Fluorescence ,Cytogenetics ,Mice ,chemistry.chemical_compound ,Species Specificity ,Centrifugation, Density Gradient ,Genetics ,medicine ,Animals ,Constitutive heterochromatin ,Trypsin ,Repeated sequence ,Genetics (clinical) ,Fluorescent Dyes ,Base Sequence ,Staining and Labeling ,Whales ,Karyotype ,DNA ,Haplorhini ,Molecular biology ,Genetic Techniques ,chemistry ,Quinacrine ,Female ,Developmental biology ,Densitometry - Abstract
The constitutive heterochromatin, as demonstrated by the C band technique, may be subdivided into a number of categories when other characteristics are considered. The responses to fluorochromes QM and 33258 Hoechst, the behavior following G band staining, the repetitive DNA content, and many other criteria are useful for the classification of heterochromatin. The heterochromatin patterns of three mammalian species are presented to demonstrate that within each karyotype there may be several different types of C bands. In general, a correlation may also be made between GC-rich satellite DNA and dull (or negative) Q fluorescence, and between AT-rich satellite DNA and bright Q, fluorescence.
- Published
- 1974
49. Reconstruction of Double-Stranded Bacterial rDNA from the Partially Purified Complementary Strands
- Author
-
Andor Udvardy, Pál Venetianer, and Magdolna Droppa
- Subjects
DNA, Bacterial ,Salmonella typhimurium ,Sucrose ,Salmonella ,Bacillus subtilis ,Tritium ,medicine.disease_cause ,Biochemistry ,Chromatography, DEAE-Cellulose ,DNA sequencing ,chemistry.chemical_compound ,Albumins ,Centrifugation, Density Gradient ,Escherichia coli ,medicine ,Base Sequence ,biology ,Temperature ,Nucleic Acid Hybridization ,Ribosomal RNA ,biology.organism_classification ,Molecular biology ,Molecular Weight ,chemistry ,Duplex (building) ,Electrophoresis, Polyacrylamide Gel ,Phosphorus Radioisotopes ,Double stranded ,DNA - Abstract
Earlier we described a method for the purification of the transcribing strand of Salmonella typhimurium rDNA. Here we report the purification of the complementary (minus) strand of Escherichia coli and Salmonella typhimuriunz rDNA, by means of partial reassociation of total bacterial DNA, chromatography on hydroxyapatite, on methylalbumin-kieselguhr, and again on hydroxyapatite. A method is presented for the measurement of rDNA(minus). From the purified complementary strands of rDNA a stable duplex has been reconstructed with nearly 50°/, rDNA content. DNA sequences coding for ribosomal RNA occur probably in six copies in the chromosome of Escherichia coli, comprising 0.3-0.4°/0 of the DNA [l]. The same is true for Salmonella typhimurium. Several procedures have been published for the purification of the transcribing (further : plus) strand of this rDNA in the form of rRNA-DNA hybrids from Bacillus subtilis, E. coli and S. typhimurium [2-51, but no successful purification of the double-stranded bacterial rDNA has been achieved. Here we report the partial purification of the non-transcribing (further : minus) strand of bacterial rDNA, a modified version of our earlier procedure for the purification of the plus strand [5], the reconstruction of a double-stranded structure from the complementary strands and characterization of the resulting rDNA duplex.
- Published
- 1973
50. The primary structure of yeast glutamic acid tRNA specific to the GAA codon
- Author
-
Tyunosin Ukita, Keiichi Takeishi, Mitsuaki Yoshida, Tsunemasa Irie, and Tomowo Kobayashi
- Subjects
Oligonucleotides ,Saccharomyces cerevisiae ,Wobble base pair ,Biology ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,Chromatography, DEAE-Cellulose ,Micrococcus ,Ribonucleases ,Glutamates ,RNA, Transfer ,Anticodon ,Escherichia coli ,Animals ,Urea ,RNA, Messenger ,Codon ,Pancreas ,Polyribonucleotide Nucleotidyltransferase ,Base Sequence ,Adenine Nucleotides ,Phosphoric Diester Hydrolases ,Venoms ,Nucleic acid sequence ,Protein primary structure ,Snakes ,Glutamic acid ,Ribonucleotides ,Alkaline Phosphatase ,Chromatography, Ion Exchange ,Guanine Nucleotides ,Yeast ,Biochemistry ,Transfer RNA ,Spectrophotometry, Ultraviolet ,Chromatography, Thin Layer ,Glutamic acid tRNA ,Nucleoside - Abstract
The total nucleotide sequence of tRNAGlu3 from baker's yeast was determined. This tRNA specifically recognizes the GAA but not the GAG codon for glutamic acid. The existence of a minor nucleoside, 2-thiouridine-5-acetic acid methyl ester (S), was confirmed at the “Wobble position” in the anticodon of this tRNA. The specificity of the coding properties of this tRNA can be explained in terms of the structure and position of this minor base.
- Published
- 1974
Catalog
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