Reaction: GTP + (phosphate)n = GDP + (phosphate)n+1
Other name(s): ppk2 (gene name); polyphosphate kinase 2
Systematic name: GTP:polyphosphate phosphotransferase
Comments: Polyphosphate kinase 2, characterized from the bacterium Pseudomonas aeruginosa, uses inorganic polyphosphate as a donor to convert GDP to GTP. The enzyme can also act on ADP (cf. EC 18.104.22.168, ATP-polyphosphate phosphotransferase), but with lower activity. The enzyme has only a trivial activity in the opposite direction (synthesizing polyphosphate from GTP). The GTP that is produced is believed to be consumed by EC 22.214.171.124, mannose-1-phosphate guanylyltransferase, for production of alginate during stationary phase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
1. Zhang, H., Ishige, K. and Kornberg, A. A polyphosphate kinase (PPK2) widely conserved in bacteria. Proc. Natl. Acad. Sci. USA 99 (2002) 16678-16683. [PMID: 12486232]
2. Ishige, K., Zhang, H. and Kornberg, A. Polyphosphate kinase (PPK2), a potent, polyphosphate-driven generator of GTP. Proc. Natl. Acad. Sci. USA 99 (2002) 16684-16688. [PMID: 12482933]