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

AUTOR(ES)

Pao, C C

RESUMO

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.

Documentos Relacionados

• Energy deprivation and guanosine 5'-diphosphate 3'-diphosphate synthesis in cyanobacteria.
• Role of Guanine Nucleotides in Protein Synthesis. Elongation Factor G and Guanosine 5′-Triphosphate,3′-Diphosphate
• Influence of amino acid starvation on guanosine 5'-diphosphate 3'-diphosphate basal-level synthesis in Escherichia coli.
• Positive control of lac operon expression in vitro by guanosine 5′-diphosphate 3′-diphosphate
• Identification of the bacterial alarmone guanosine 5′-diphosphate 3′-diphosphate (ppGpp) in plants