Abstact

The increasing global incidence rate of nontuberculous mycobacteria pulmonary infections is an emerging public health crisis, with Mycobacterium abscessus (Mab) being one of the most virulent and treatment-refractory of these pathogens. Mab exhibits extensive intrinsic and acquired drug resistance mechanisms that neutralize most antimicrobials against this pathogen, causing a clinical conundrum. As Mab relies on oxidative phosphorylation as its main energy source, its essential F-ATP synthase is a promising drug target but remains poorly understood due to a lack of host expression systems. Here, we present the expression, isolation, and structural characterization of Mab's F-ATP synthase. Cryo-EM reveals three nucleotide-driven rotational states at atomic resolution, highlighting key catalytic centers, a mycobacteria-specific α-subunit extension involved in the inhibition of ATP hydrolysis, energy transmission via the γε-stalk, and mechanochemical coupling by the δ-subunit. The structural blueprint allows precise target engagement and optimization of hits-to-leads and existing anti-Mab inhibitors targeting the engine.