Inhibiting Mycobacterium tuberculosis CoaBC by targeting an allosteric site

Abstract

AbstractCoenzyme A (CoA) is a fundamental co-factor for all life, involved in numerous metabolic pathways and cellular processes, and its biosynthetic pathway has raised substantial interest as a drug target against multiple pathogens includingMycobacterium tuberculosis. The biosynthesis of CoA is performed in five steps, with the second and third steps being catalysed in the vast majority of prokaryotes, includingM. tuberculosis, by a single bifunctional protein, CoaBC. Depletion of CoaBC was found to be bactericidal inM. tuberculosis. Here we report the first structure of a full-length CoaBC, from the model organismMycobacterium smegmatis, describe how it is organised as a dodecamer and regulated by CoA thioesters. A high-throughput biochemical screen focusing on CoaB identified two inhibitors with different chemical scaffolds. Hit expansion led to the discovery of potent and selective inhibitors ofM. tuberculosisCoaB, which we show to bind to a cryptic allosteric site within CoaB.