Naturally occurring Dinactin targets cpsA of LytR-Cps2A-Psr family protein as well as kills Mycobacterium tuberculosis by disrupting proton motive force

Abstract Tuberculosis is still a global threat, and new drugs are desperately needed to combat the spread of multidrug-resistant Mycobacterium tuberculosis. Historically, natural products have been an important source of drugs against infectious diseases, like tuberculosis. Here, we identified a natural macrotetrolide dinactin with antituberculosis activity against susceptible and non-replicating Mycobacterium tuberculosis. Dinactin can synergistically enhance the antituberculosis effect of rifampicin and isoniazide against wild-type and drug-resistant strains. Dinactin also demonstrates antituberculosis activity in macrophage and Galleria mellonella models. Interestingly, dinactin possesses the properties of the ionophore. It not only enhances cations transport across the cell membrane and can alter membrane permeability but also causes the dissipation of proton motive force and metabolic perturbations. By selecting spontaneous resistant mutants and whole genome sequencing, we successfully identified non-synonymous single nucleotide polymorphisms in the cpsA gene of the LytR-Cps2A-Psr family. The dinactin-resistant mutants decrease the in vitro drug sensitivity to dinactin without cross-resistant with first-line antituberculosis drugs. Subsequently, genetic studies and molecular biology assays confirm the cpsA as the principal target. These findings suggest that dinactin could be a promising antibiotic for treating drug-resistant tuberculosis.