Role of peptide chain elongation factor G in guanosine 5'-diphosphate 3'-diphosphate synthesis.

Abstract

In a wild-type strain (relA+) of Escherichia coli, starvation of amino acid led to an immediate cessation of the synthesis of stable ribonucleic acids, together with the accumulation of an unusual nucleotide, guanosine 5'-diphosphate 3'-diphosphate, commonly known as ppGpp. This compound also accumulated during heat shock. When temperature-sensitive protein synthesis elongation factor G (EF-G) was introduced into E. coli NF859, a relA+ strain, the synthesis of ppGpp was reduced to approximately one-half that of wild-type EF-G+ cells at a nonpermissive temperature of 40 degrees C. Furthermore, fusidic acid, an inhibitor of protein synthesis which specifically inactivates EF-G, prevented any accumulation of ppGpp during the heat shock. We suggest that a functional EF-G protein is necessary for ppGpp accumulation under temperature shift conditions, possibly by mediating changes in the function of another protein, the relA gene product. However, EF-G is probably not required for the synthesis of ppGpp during the stringent response, since its inactivation did not prevent ppGpp accumulation during amino acid starvation.

• Authors: C C Pao, J Fleckenstein, B T Dyess
• Journal: Journal of bacteriology (J Bacteriol) Vol. 145 Issue 1 Pg. 429-33 (Jan 1981) ISSN: 0021-9193 [Print] United States
• PMID: 7007322 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Amino Acids
• Bacterial Proteins
• Guanine Nucleotides
• Peptide Elongation Factors
• Guanosine Tetraphosphate

Topics

• Amino Acids (metabolism)
• Bacterial Proteins (biosynthesis)
• Escherichia coli (genetics, metabolism)
• Guanine Nucleotides (biosynthesis)
• Guanosine Tetraphosphate (biosynthesis)
• Hot Temperature
• Mutation
• Peptide Elongation Factors (physiology)