Using Proteolytic Hypomorphs to Detect Small Molecule Mechanism of Action.

With increasing prevalence of antimicrobial resistance, a fundamental goal of antibiotic discovery is to uncover new small molecules that prevent growth of pathogenic bacteria through diverse mechanisms of action. This goal is particularly pertinent for tuberculosis, caused by Mycobacterium tuberculosis. In this chapter, we describe the application of a chemical-genetic method, PROSPECT (primary screening of strains to prioritize expanded chemistry and targets), for sensitively detecting small molecule bioactivity using a pooled panel of hypomorphs (strains depleted in a particular essential gene) of M. tuberculosis. We describe statistical and heuristic approaches to assign small molecule mechanism of action from the resulting chemical-genetic interaction profiles.