Catalyzes the cyanide-resistant oxidation of ubiquinol and the reduction of molecular oxygen to water, but does not translocate protons and consequently is not linked to oxidative phosphorylation. May increase respiration when the cytochrome respiratory pathway is restricted, or in response to low temperatures. In S.guttatum the alternative respiratory pathway is thermogenic. 2 a ubiquinol + O2 = 2 a ubiquinone + 2 H2O Binds 2 iron ions per subunit. Not sensitive to pyruvate. Is in a constitutively active state. When the two monomeric subunits are covalently linked by a S-S bond, the enzyme is essentially inactive. Homodimer; disulfide-linked. Mitochondrial, possibly in the inner surface of the inner mitochondrial membrane. By salicylic acid. The 3 alternative oxidase proteins detected in S.guttatum, with apparent MW of 35 kDa, 36 kDa and 37 kDa, may be post-translationally modified products of the same AOX1 gene. Belongs to the alternative oxidase family. The beetle's brothel - Issue 107 of July 2009