title: On the function of the various quinone species in Escherichia coli.
abstract: 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.
authors.affiliation: Molecular Microbial Physiology group, Swammerdam Institute for Life Sciences, University of Amsterdam, The Netherlands.
authors.forename: Poonam
authors.initials: P
authors.lastname: Sharma
authors.forename: Maarten J
authors.initials: MJ
authors.lastname: Teixeira de Mattos
authors.forename: Klaas J
authors.initials: KJ
authors.lastname: Hellingwerf
authors.forename: Martijn
authors.initials: M
authors.lastname: Bekker
mesh_terms: D000332:Aerobiosis; D004579:Electron Transport; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D011809:Quinones / Q000378:metabolism*; D014451:Ubiquinone / Q000378:metabolism; D024482:Vitamin K 2 / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D011809:Quinones; D024482:Vitamin K 2; D014451:Ubiquinone; C013917:demethylmenaquinone