hydroxylamine [CPD:C00192];
ferricytochrome c [CPD:C00125]
Product
nitric oxide [CPD:C00533];
ferrocytochrome c [CPD:C00126];
H+ [CPD:C00080]
Comment
The enzyme, characterized from the anaerobic ammonium-oxidizing (anammox) bacterium Kuenenia stuttgartiensis, is very similar to EC 1.7.2.6, hydroxylamine dehydrogenase. Both enzymes are homotrimeric enzymes in which each subunit contains seven c-type hemes and one specialized P460-type heme that is bound to a tyrosine residue in an adjacent subunit. However, this enzyme catalyses only the 3 electron oxidation of hydroxylamine, forming nitric oxide, and is not capable of performing further oxidation to form nitrite.