期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:2000
卷号:97
期号:26
页码:14168-14171
DOI:10.1073/pnas.011518098
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要: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.