7.1.1.7	physiological function	besides its oxidase activity, cytochrome bd is a genuine quinol peroxidase that reduces hydrogen peroxide to water. The enzyme does not display catalase activity	752197	
7.1.1.7	physiological function	both cytochrome bd-type CydAB, EDC 7.1.1.7, and cytochrome aa3-type menaquinol QoxAB oxidase, EC 7.1.1.5, are used for respiration under different oxygen tensions. Possession of both terminal oxidases is important in infection. In air, the CydAB bd-type oxidase is essential for aerobic respiration and intracellular replication, and cydAB mutants are highly attenuated in mice. At 1% O2 (vol/vol), both oxidases are functional, and the presence of either is sufficient for aerobic respiration and intracellular replication. At 0.2% O2 (vol/vol), both oxidases are necessary for maximum growth	-, 750736	
7.1.1.7	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	
7.1.1.7	physiological function	inactivation of cydA or cydB by gene disruption results in loss of d-heme absorbance at 631 nm. Inactivation of cydA has no effect on the ability of Mycobacterium smegmatis to exit from stationary phase at 37 or 42°C. No discernible growth defect of the mutant is observed under moderately aerobic conditions, while the mutant displays a significant growth disadvantage when cocultured with the wild type under extreme microaerophilia. The cydA mutant displays a competitive growth disadvantage in the presence of the terminal oxidase inhibitor, cyanide, when cocultured with wild type at 21% air saturation in an oxystat	727738	
7.1.1.7	physiological function	inactivation of cydA or cydB gene disruption results in loss of d-heme absorbance at 631 nm	727738	
7.1.1.7	physiological function	induction of cytochrome bd helps Salmonella grow and respire in the presence of inhibitory nitric oxide	743207	
7.1.1.7	physiological function	loss of the flavohemoglobin Hmp and cytochrome bd-I elicit high sensitivity to NO-mediated growth inhibition. The subunits cydAB mutant displays an attenuated colonisation phenotype in a mouse model after 2 days	743822	
7.1.1.7	physiological function	the bd oxidase functions in controlling electron flux. A mutant lacking the cytochrome bd oxidase shows developmental defects during growth on buffered rich medium plates with glucose as the energy substrate. Cytochrome bd oxidase is essential for the bacterium to grow and complete its developmental cycle under oxygen limitation	-, 750975	
7.1.1.7	physiological function	the enzyme contributes to bacterial resistance to nitric oxide and hydrogen peroxide	741966	
7.1.1.7	physiological function	the enzyme contributes to Escherichia coli survival in the mouse bladder	-, 743822	
7.1.1.7	physiological function	the enzyme is important for survival of Mycobacterium smegmatis under peroxide and antibiotic-induced stress	-, 743792	
7.1.1.7	physiological function	the expression of cytochrome bd enhances bacterial tolerance to nitrosative stress	741957	
7.1.1.7	physiological function	the interheme electron backflow reaction induced by photodissociation of CO from heme d in one-electron reduced cytochrome bd-I comprises two kinetically different phases: the fast electron transfer from heme d to heme b595 within 0.2-1.5 micros and the slower electron equilibration with tau of about 16 micros. At 200 ns, there is no electron transfer	743604	
7.1.1.7	physiological function	the unresolved photodissociation of CO is followed by a four-phased recombination with characteristic times of about 20 micros, 250 micros, 1.1 ms, and 24 ms. The 20x02micros phase most likely reflects bimolecular recombination of CO with heme d. The 250x02micros phase is heterogeneous and includes recombination of CO with about 7% of heme b595 and transition of heme d from a pentacoordinate to a transient hexacoordinate state in this enzyme population. The 24x02ms transition probably reflects a return of heme d to the pentacoordinate state in the same protein fraction. The 1.1x02ms phase reflects a recombination of CO with about 15% of heme b558	749941	
7.1.1.7	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