7.1.1.3	malfunction	deletion of the cydAB genes for cytochrome bd has no obvious influence on growth, whereas the lack of the cyoBACD genes for cytochrome bo3 severely reduced the growth rate and the cell yield	725289	
7.1.1.3	malfunction	loss of cytochrome bd-I oxidase subunit II (gene cydB) causes diminished respiration rates, impaired motility and enhanced acid resistance. CydB cells contain elevated heme d, particularly at low pH. The GABA/glutamate gadC antiporter is highly up-regulated in cydB cells. Eschrichia coli can compensate for the loss of cytochrome bd-I activity	-, 715509	
7.1.1.3	metabolism	Gluconobacter oxydans oxidizes a variety of substrates in the periplasm by membrane-bound dehydrogenases, which transfer the reducing equivalents to ubiquinone. Two quinol oxidases, cytochrome bo3 and cytochrome bd, then catalyze transfer of the electrons from ubiquinol to molecular oxygen	725289	
7.1.1.3	physiological function	cytochrome bd-II-mediated quinol oxidation prevents the accumulation of NADH, whereas GABA synthesis/antiport maintains the proton motive force for ATP production	-, 715509	
7.1.1.3	physiological function	cytochrome bo is a four-subunit quinol oxidase in the aerobic respiratory chain of Escherichia coli and functions as a redox-coupled proton pump	-, 714141, 715399	
7.1.1.3	physiological function	cytochrome bo-type ubiquinol oxidase in the aerobic respiratory chain of Escherichia coli catalyzes the reduction of dioxygen to water with ubiquinol-8, and utilizes the redox reactions to drive vectorial translocation of protons across the cytoplasmic membrane	-, 715000	
7.1.1.3	physiological function	cytochrome bo3 might be a rate-limiting factor of the respiratory chain	725289	
7.1.1.3	physiological function	cytochrome bo3 ubiquinol oxidase from Escherichia coli is a four-subunit heme-copper oxidase that catalyzes the four-electron reduction of O2 to water and functions as a proton pump	716311	
7.1.1.3	physiological function	cytochrome bo3 ubiquinol oxidase serves as part of a proton loading site that regulates proton translocation across the protein matrix of the enzyme	714169	
7.1.1.3	physiological function	in respiratory mutants, both O2-consumption and aerobic growth are severely impaired by sulfide when respiration is sustained by the bo3 oxidase alone	752188	
7.1.1.3	physiological function	in respiratory mutants, both O2-consumption and aerobic growth are unaffected by up to 200 microM sulfide when cytochrome bd-I or bd-II enzyme actes as the only terminal oxidase. Wild-type Escherichia coli shows sulfide-insensitive respiration and growth under conditions favouring the expression of bd oxidases	752188	
7.1.1.3	physiological function	in the absence of the tightly bound quinone, a strongly diminished rate of electrocatalytic reduction of oxygen is detected, which can be restored by adding quinones. The stabilization of the radical is not necessary for the oxygen reaction. The reaction mechanism should involve a one electron transfer step from the quinone radical to the next electron acceptor, the heme b	749941	
7.1.1.3	physiological function	overexpression of cytochrome c ScyA facilitates growth despite nitrite inhibition by enhancing nitrite resistance of the cbb3 oxidase. ScyA either increases electron flow to the cbb3 oxidase;, or ScyA promotes nitrite resistance of the cbb3 oxidase, possibly by direct interaction	751510	
7.1.1.3	physiological function	the bo-type ubiquinol oxidase is functioning as a proton pump	714285	
7.1.1.3	physiological function	the enzyme contributes to oxidative stress resistance and dioxygen tolerance	-, 743596	
7.1.1.3	physiological function	the enzyme is important during murine infection, required for the intracellular growth in air, essential for aerobic respiration and intracellular replication and confers resistance to reactive nitrogen species	742647	
7.1.1.3	physiological function	the enzyme is important for survival of Mycobacterium smegmatis under peroxide and antibiotic-induced stress	-, 743792	
7.1.1.3	physiological function	the enzyme prevents respiratory inhibition by endogenous and exogenous hydrogen sulfide	743301	
7.1.1.3	physiological function	the ubiquinol oxidase, cytochrome b03, of Escherichia coli is a member of the respiratory heme-copper oxidase family and conserves energy from the reduction of dioxygen to water by translocation of protons across the bacterial membrane	714135	
7.1.1.3	physiological function	when cystine is provided and sulfide levels rise, Escherichia coli becomes strictly dependent upon cytochrome bd oxidase for continued respiration. Low-micromolar levels of sulfide inhibit the proton-pumping cytochrome bo oxidase. In the absence of the back-up cytochrome bd oxidase, growth fails. Exogenous sulfide elicits the same effect	743301