Bacterial respiratory enzymes

Bacterial respiratory enzymes are a diverse group of membrane-bound proteins that constitute the electron transport chain (ETC) and oxidative phosphorylation machinery in bacteria (Cook et al., 2014, J Biol Chem). These enzymes, including NADH dehydrogenases, succinate dehydrogenases, cytochrome complexes, and ATP synthases, work coordinately to generate a proton motive force across the cytoplasmic membrane, which is then used to drive the synthesis of ATP (Bald et al., 2017, Nat Commun). Because bacterial respiratory pathways often differ significantly from their eukaryotic mitochondrial counterparts—utilizing alternative electron donors and acceptors—they represent attractive targets for narrow-spectrum and multi-drug resistant (MDR) antimicrobial therapy (Hards et al., 2018, Front Microbiol). Drugs targeting these enzymes, such as bedaquiline for Mycobacterium tuberculosis, act by disrupting energy metabolism, leading to bacterial stasis or death (Andries et al., 2005, Science). Telacebec (Q203) is another example, targeting the cytochrome bcc complex to inhibit respiration in mycobacteria (Pethe et al., 2013, Nat Med). Other compounds like clofazimine and phenothiazines target the type II NADH dehydrogenase (NDH-2), an enzyme absent in the human mitochondrial respiratory chain (Yano et al., 2011, J Biol Chem). However, the high degree of diversity among bacterial species and the potential for compensatory respiratory pathways present challenges in drug development and the emergence of resistance (Cook et al., 2017, Microbiol Spectr). Safety concerns often involve potential cross-reactivity with human mitochondrial enzymes or off-target effects like QT prolongation (Belardinelli et al., 2013, PLoS ONE). Despite these challenges, the bioenergetic machinery remains a cornerstone for developing next-generation antibiotics against persistent pathogens.

Other names

Bacterial electron transport chainBacterial oxidative phosphorylation systemBacterial respiratory chainBacterial respiratory chain enzymes

Inhibition of ATP synthase, inhibition of the cytochrome bcc complex (QcrB), and inhibition of NADH dehydrogenase (NDH-2) to disrupt the proton motive force and ATP production (Andries et al., 2005; Pethe et al., 2013; Yano et al., 2011).