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A new factor from Escherichia coli affects translocation of mRNA.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 1995 Nov 03; Vol. 270 (44), pp. 26377-81. - Publication Year :
- 1995
-
Abstract
- Reconstitution of protein synthesis from purified translation factors on ribosomes from Escherichia coli has revealed the requirement for a protein, W, that affects chain elongation and is essential to reconstitute the process (Ganoza, M. C., Cunningham, C., and Green, R. M. (1985) Proc. Natl. Acad. Sci. U.S.A. 82, 1648-1652). We report that W has no effect on initiation complex formation by 30 or 70 S ribosomes or on the association of ribosomal subunits, peptide bond synthesis, or binding Ala-tRNA, which is the second amino acid of the coat protein of the MS2 RNA virion. W has a pronounced effect on tripeptide synthesis, and is obligatory for the synthesis of the coat protein or of the hexapeptide encoded by f2am3 RNA. Extracts from a temperature-sensitive mutant of the translocase, EF-G, were purified free of the W protein and were used to score for translocation defects. W is required for binding Ser-tRNA, the third N-terminal amino acid of the MS2 or f2 RNA coat protein to ribosomes bearing fMet-Ala-tRNA, as well as for the ejection of deacyl-tRNA from ribosomes, which occurred concomitant with the binding of the Ser-tRNA. We propose that W functions by ejecting tRNAs from ribosomes in a step that precedes the movement of mRNA during translocation.
- Subjects :
- Bacterial Proteins isolation & purification
Capsid biosynthesis
Escherichia coli genetics
GTP Phosphohydrolase-Linked Elongation Factors metabolism
Kinetics
Levivirus metabolism
Peptide Elongation Factor G
Peptide Elongation Factors isolation & purification
Peptide Elongation Factors metabolism
RNA, Transfer, Ala metabolism
RNA, Transfer, Ser metabolism
Virion metabolism
Bacterial Proteins metabolism
Escherichia coli metabolism
Protein Biosynthesis
RNA, Messenger metabolism
RNA, Transfer, Amino Acid-Specific metabolism
Ribosomes metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 270
- Issue :
- 44
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 7592851
- Full Text :
- https://doi.org/10.1074/jbc.270.44.26377