Rv2985 diadenosine polyphosphatase from M. tuberculosis, an “invasion” enzyme homolog and potential novel antibiotic target

BIOL 82

Joshua G. Thomson, Julian N. Ramos, and Suzanne F. O'Handley, sfosch@rit.edu. Department of Chemistry, Rochester Institute of Technology, 85 Lomb Memorial Dr, Rochester, NY 14623
The Nudix hydrolases cleave nucleoside diphosphates linked to some moiety, x, and are identified by the common signature sequence: GX5E7REUXEEXGU (U= I, L, or V). Rv2985 diadenosine polyphosphatase from M. tuberculosis is a homolog to diadenosine polyphosphatase “invasion enzymes” from other pathogenic bacteria. Rv2985 cleaves Ap4A, Ap5A and Ap6A with nearly comparable activity. Characteristic of Nudix hydrolases, Rv2985 requires a divalent metal cofactor and has an alkaline pH optimum. Regardless of the substrate, ATP is always a resulting product, and it is always the fourth phosphorus from one of the adenosines which is attacked during hydrolysis. We have subcloned and purified a His-tagged protein, which retains full expression, solubility, and activity, as compared to wild type, and purifies by affinity chromatography as one pure band. Blocking the ability of a pathogen such as M. tuberculosis to be able to invade its human host may be an excellent target for the development of new antibiotics. Supported by an NIH AREA grant.