Inhibiting Mycobacterium tuberculosis CoaBC by targeting an allosteric site

Vitor Mendes, Simon R Green, Joanna C Evans, Jeannine Hess, Michal Blaszczyk , Christina Spry, Owain Bryant , James Cory-Wright , Daniel S-H Chan, Pedro H M Torres, Zhe Wang, Navid Nahiyaan , Sandra O’Neill, Sebastian Damerow, John Post, Tracy Bayliss, Sasha L Lynch, Anthony G Coyne, Peter C Ray, Chris Abell, Kyu Y Rhee, Helena I M Boshoff, Clifton E Barry 3rd , Valerie Mizrahi, , Tom L Blundell.

Nat Commun. 2021 Jan 8;12(1):143. doi: 10.1038/s41467-020-20224-x. PMID: 33420031

Coenzyme 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 including Mycobacterium tuberculosis. The biosynthesis of CoA is performed in five steps, with the second and third steps being catalysed in the vast majority of prokaryotes, including M. tuberculosis, by a single bifunctional protein, CoaBC. Depletion of CoaBC was found to be bactericidal in M. tuberculosis. Here we report the first structure of a full-length CoaBC, from the model organism Mycobacterium 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 of M. tuberculosis CoaB, which we show to bind to a cryptic allosteric site within CoaB.