Bacillus subtilis expresses two kinds of haem-A-containing terminal oxidases.
The expression of two different aa3-type cytochrome oxidases is demonstrated in Bacillus subtilis. One of them (denoted caa3-605), was predicted by DNA-sequencing of Bacillus cytochrome oxidase genes, but has not been found previously. It contains covalently bound haem C in subunit II and is very similar to the enzyme previously described in the thermophilic bacterium PS3. The other oxidase (denoted aa3-600) deviates from most known oxidases of aa3 type, and is probably identical with the oxidase described by de Vrij et al. [de Vrij, W., Azzi, A. & Konings, W. N. (1983) Eur. J. Biochem. 131, 97-103]. It shows no immunological cross-reactivity to the PS3 enzyme and differs from this spectroscopically; it contains no CuA and does not oxidise cytochrome c despite of its haem-A chromophores. It catalyses oxidation of quinols, which is proposed to be its physiological function.
Lauraeus
M
M
Department of Medical Chemistry, University of Helsinki, Finland.
Haltia
T
T
Saraste
M
M
Wikström
M
M
D001412:Bacillus subtilis / Q000201:enzymology*; D004578:Electron Spin Resonance Spectroscopy; D003576:Electron Transport Complex IV / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D006418:Heme / Q000032:analysis*; D013053:Spectrophotometry
D006418:Heme; D003576:Electron Transport Complex IV