Identification of cytochromes o and a3 as functional terminal oxidases in the thermophilic bacterium, PS3

AbstractLow-temperature photodissociation spectra of membranes from the thermophile PS3 reveal cytochromes o and a3. The latter reacts with O2 at −103°C to give a light-insensitive compound(s), but the initial stages of O2 binding to cytochrome o could not be studied under these conditions. Photochemical action spectra identify cytochromes a3 and o, but not a CO-binding c-type cytochrome, as functional terminal oxidases in this bacterium