PMID:15941717

From EcoliWiki
Jump to navigation Jump to search
Citation

Kim, J, Shen, R, Olcott, MC, Rajagopal, I and Mathews, CK (2005) Adenylate kinase of Escherichia coli, a component of the phage T4 dNTP synthetase complex. J. Biol. Chem. 280:28221-9

Abstract

Adenylate kinase, which catalyzes the reversible ATP-dependent phosphorylation of AMP to ADP and dAMP to dADP, can also catalyze the conversion of nucleoside diphosphates to the corresponding triphosphates. Lu and Inouye (Lu, Q., and Inouye, M. (1996) Proc. Natl. Acad. Sci. U. S. A. 93, 5720-5725) showed that an Escherichia coli ndk mutant, lacking nucleoside diphosphate kinase, can use adenylate kinase as an alternative source of nucleoside triphosphates. Bacteriophage T4 can reproduce in an Escherichia coli ndk mutant, implying that adenylate kinase can meet a demand for deoxyribonucleoside triphosphates that increases by up to 10-fold as a result of T4 infection. In terms of kinetic linkage and specific protein-protein associations, NDP kinase is an integral component of T4 dNTP synthetase, a multienzyme complex containing phage-coded enzymes, which facilitates the synthesis of dNTPs and their flow into DNA. Here we asked whether, by similar criteria, adenylate kinase of the host cell is also a specific component of the complex. Experiments involving protein affinity chromatography, immunoprecipitation, optical biosensor measurements, and glutathione S-transferase pulldowns demonstrated direct interactions between adenylate kinase and several phage-coded enzymes, as well as E. coli nucleoside diphosphate kinase. These results identify adenylate kinase as a specific component of the complex. The rate of DNA synthesis after infection of an ndk mutant was found to be about 40% of the rate seen in wild-type infection, implying that complementation of the missing NDP kinase function by adenylate kinase is fairly efficient, but that adenylate kinase becomes rate-limiting for DNA synthesis when it is the sole source of dNTPs.

Links

PubMed Online version:10.1074/jbc.M502201200

Keywords

Adenylate Kinase/isolation & purification; Adenylate Kinase/metabolism; Bacteriophage T4/enzymology; Bacteriophage T4/genetics; Chromatography, Affinity; DNA Replication; Escherichia coli/enzymology; Escherichia coli/genetics; Glutathione Transferase/isolation & purification; Glutathione Transferase/metabolism; Kinetics; Models, Biological; Multienzyme Complexes/metabolism

Significance

You can help EcoliWiki by summarizing why this paper is useful

Useful Materials and Methods

You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.

Annotations

<annotationlinks/>

EcoliWiki Links

Add links to pages that link here (e.g. gene, product, method pages)

References

See Help:References for how to manage references in EcoliWiki.