Insights into the Physiology and Metabolism of a Mycobacterial Cell in an Energy-Compromised State

M. smegmatis generates an inadequate amount of energy by substrate-level phosphorylation and mandatorily requires oxidative phosphorylation (OXPHOS) for its growth and metabolism. Here, we explored the influence of suboptimal OXPHOS on M. smegmatis physiology and metabolism. M. smegmatis harbors two identical copies of the atpD gene, which codes for the ATP synthase β subunit. Here, we carried out the deletion of only one copy of atpD in M. smegmatis to understand the bacterial survival response in an energy-deprived state. M. smegmatis Δ atpD shows remarkable phenotypic, metabolic, and physiological differences from the wild type. Our study thus establishes M. smegmatis Δ atpD as an energy-compromised mycobacterial strain, highlights the importance of ATP synthase in mycobacterial physiology, and further paves the way for the identification of novel antimycobacterial drug targets.