Microbial electron transport cytochromes

Microbial electron transport cytochromes are heme-containing proteins that play a central role in the respiratory chains of bacteria, archaea, and some fungi. These proteins facilitate the sequential transfer of electrons from donors like NADH or succinate to terminal acceptors such as oxygen, a process coupled to the generation of a proton gradient for ATP synthesis (Borisov et al., 2021). In pathogenic organisms like Mycobacterium tuberculosis, specific complexes such as the cytochrome bcc complex and the cytochrome bd oxidase are vital for metabolic flexibility and survival within the host environment (Pethe et al., 2013). Because certain microbial cytochromes, particularly the bd-type oxidases, are structurally distinct from human mitochondrial cytochromes, they serve as attractive targets for selective antimicrobial therapy (Cook et al., 2021). Inhibitors like Telacebec (Q203) target the QcrB subunit of the bcc complex, leading to a rapid depletion of intracellular ATP and bacterial death (Kang et al., 2014). Research into these targets is particularly focused on overcoming multi-drug resistance in tuberculosis and other recalcitrant bacterial infections.

Other names

Bacterial respiratory cytochromesCytochrome bcc complexCytochrome bd oxidaseCytochrome c oxidase (microbial)Heme-proteins of the microbial respiratory chain

Inhibition of electron transfer through the cytochrome complexes, typically by binding to the quinol oxidation (Qo) or reduction (Qi) sites, thereby disrupting the proton motive force and ATP production.