6pbz

Structural highlights

Function

GPPA_ECOLI Catalyzes the conversion of pppGpp to ppGpp. Guanosine pentaphosphate (pppGpp) is a cytoplasmic signaling molecule which together with ppGpp controls the 'stringent response', an adaptive process that allows bacteria to respond to amino acid starvation, resulting in the coordinated regulation of numerous cellular activities (PubMed:6130093, PubMed:8394006). In vitro, can hydrolyze pppGp (PubMed:6130093). Also has exopolyphosphatase activity, catalyzing the release of orthophosphate by processive hydrolysis of the phosphoanyhydride bonds of polyphosphate chains (1000 residues) (PubMed:8394006).^{[1] [2]}

References

1. ↑ Hara A, Sy J. Guanosine 5'-triphosphate, 3'-diphosphate 5'-phosphohydrolase. Purification and substrate specificity. J Biol Chem. 1983 Feb 10;258(3):1678-83. PMID:6130093
2. ↑ Keasling JD, Bertsch L, Kornberg A. Guanosine pentaphosphate phosphohydrolase of Escherichia coli is a long-chain exopolyphosphatase. Proc Natl Acad Sci U S A. 1993 Aug 1;90(15):7029-33. PMID:8394006