The respiratory chain of Escherichia coli contains three quinones. Menaquinone and demethylmenaquinone have low midpoint potentials and are involved in anaerobic respiration, while ubiquinone, which … has a high midpoint potential, is involved in aerobic and nitrate respiration. Here, we report that demethylmenaquinone plays a role not only in trimethylaminooxide-, dimethylsulfoxide- and fumarate-dependent respiration, but also in aerobic respiration. Furthermore, we demonstrate that demethylmenaquinone serves as an electron acceptor for oxidation of succinate to fumarate, and that all three quinol oxidases of E. coli accept electrons from this naphtoquinone derivative.
Date Published: 1st Sep 2012
Journal: Not specified