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The N-terminal domain (IF2N) of bacterial translation initiation factor IF2 is connected to the conserved C-terminal domains by a flexible linker.
- Source :
-
Protein science : a publication of the Protein Society [Protein Sci] 2004 Jan; Vol. 13 (1), pp. 230-9. - Publication Year :
- 2004
-
Abstract
- Bacterial translation initiation factor IF2 is a multidomain protein that is an essential component of a system for ensuring that protein synthesis begins at the correct codon within a messenger RNA. Full-length IF2 from Escherichia coli and seven fragments of the protein were expressed, purified, and characterized using nuclear magnetic resonance (NMR) and circular dichroism (CD) methods. Interestingly, resonances of the 6 kD IF2N domain located at the extreme N terminus of IF2 can be clearly identified within the NMR spectra of the full-length 97-kD protein. (15)N NMR relaxation rate data indicate that (1) the IF2N domain is internally well ordered and tumbles in solution in a manner that is independent of the other domains of the IF2 protein, and (2) the IF2N domain is connected to the C-terminal regions of IF2 by a flexible linker. Chemical shifts of resonances within the isolated IF2N domain do not significantly differ from those of the corresponding residues within the context of the full-length 97-kD protein, indicating that IF2N is a structurally independent unit that does not strongly interact with other regions of IF2. CD and NMR data together provide evidence that Domains I-III of IF2 have unstructured and flexible regions as well as substantial helical content; CD data indicate that the helical content of these regions decreases significantly at temperatures above 35 degrees C. The features of structurally well-ordered N- and C-terminal domains connected by a flexible linker with significant helical content are reminiscent of another translation initiation factor, IF3.
- Subjects :
- Amino Acid Sequence
Circular Dichroism
Cloning, Molecular
Computer Simulation
Conserved Sequence
Electrophoresis, Polyacrylamide Gel
Escherichia coli genetics
Escherichia coli Proteins genetics
Escherichia coli Proteins isolation & purification
Escherichia coli Proteins metabolism
Models, Molecular
Molecular Sequence Data
Molecular Weight
Nuclear Magnetic Resonance, Biomolecular
Peptide Fragments analysis
Peptide Fragments chemistry
Prokaryotic Initiation Factor-2 genetics
Prokaryotic Initiation Factor-2 isolation & purification
Prokaryotic Initiation Factor-2 metabolism
Protein Structure, Secondary
Protein Structure, Tertiary
Solutions chemistry
Temperature
Escherichia coli Proteins chemistry
Prokaryotic Initiation Factor-2 chemistry
Protein Folding
Subjects
Details
- Language :
- English
- ISSN :
- 0961-8368
- Volume :
- 13
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Protein science : a publication of the Protein Society
- Publication Type :
- Academic Journal
- Accession number :
- 14691238
- Full Text :
- https://doi.org/10.1110/ps.03337604