Inorganic polyphosphate kinase and adenylate kinase participate in the polyphosphate:AMP phosphotransferase activity of Escherichia coli

Kazuya Ishige* and
Toshitada Noguchi

Biochemicals Division, YAMASA Corporation, Choshi, Chiba 288-0056, Japan

Communicated by Arthur Kornberg, Stanford University School of Medicine, Stanford, CA (received for review July 26, 1999)

Abstract

Polyphosphate kinase (PPK), responsible for the processive synthesis of inorganic polyphosphate (polyP) from ATP in Escherichia coli, can transfer in reverse the terminal phosphate residue of polyP to ADP to yield ATP. PolyP also serves as a donor in a polyP:AMP phosphotransferase (PAP) activity observed in extracts of Acinetobacter johnsonii and Myxococcus xanthus. We have found that overexpression of the gene encoding PPK results in a large enhancement of PAP activity in E. coli. The PAP activity requires both PPK and adenylate kinase in equimolar amounts. PPK and adenylate kinase form a complex in the presence of polyphosphate. We discuss a phosphotransfer mechanism that involves both enzymes and enables polyP to be a phospho-donor to AMP.

Footnotes

↵ * To whom reprint requests should be addressed. E-mail: biopro{at}yamasa.com.
Article published online before print: Proc. Natl. Acad. Sci. USA, 10.1073/pnas.011518098.
Article and publication date are at www.pnas.org/cgi/doi/10.1073/pnas.011518098
Abbreviations:

polyP,

polyphosphate;

ADK,

adenylate kinase;

PAP,

polyphosphate:AMP phosphotransferase;

PEI-TLC,

polyethyleneimine-cellulose TLC;

PPK,

polyphosphate kinase