Work

Elongation factor Tu.guanosine 3'-diphosphate 5'-diphosphate complex increases the fidelity of proofreading in protein biosynthesis: mechanism for reducing translational errors introduced by amino acid starvation.

Year: 1986

Type: article

Abstract: Complexes of elongation factor Tu (EF-Tu) with guanosine 3'-diphosphate 5'-diphosphate (ppGpp) bind to ribosomes where they slow the incorporation of aminoacyl-tRNAs into protein by inhibiting both the binding of aminoacyl-tRNA.EF-Tu.GTP ternary complexes and the formation of peptide bonds. The latter action increases the time available for aminoacyl-tRNA rejection by the ribosome and, therefore, increases the effectiveness of proofreading. Synthesis of ppGpp and the formation of EF-Tu.ppGpp occur in vivo in response to amino acid starvation. Our finding, therefore, suggests an explanation for the otherwise puzzling observation that amino acid starvation has, at most, a moderate effect on the fidelity of protein synthesis in wild-type Escherichia coli. We suggest that an EF-Tu.ppGpp-induced increase in the effectiveness of proofreading buffers the overall translational fidelity of these cells against amino acid starvation-induced errors in initial selection of aminoacyl-tRNA ternary complexes.

Source: Proceedings of the National Academy of Sciences

DOI: 10.1073/pnas.83.7.2027

Authors: D B Dix, R C Thompson

Institution: University of Colorado Boulder

Language: English

Topic: RNA and protein synthesis mechanisms

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: green

Funders: National Institutes of Health, National Institute of General Medical Sciences

Award: G2344425231