Main content area

Cytochrome cbb₃ of Thioalkalivibrio is a Na⁺-pumping cytochrome oxidase

Muntyan, Maria S., Cherepanov, Dmitry A., Malinen, Anssi M., Bloch, Dmitry A., Sorokin, Dimitry Y., Severina, Inna I., Ivashina, Tatiana V., Lahti, Reijo, Muyzer, Gerard, Skulachev, Vladimir P.
Proceedings of the National Academy of Sciences of the United States of America 2015 v.112 no.25 pp. 7695-7700
Thioalkalivibrio, cytochrome c, cytochrome-c oxidase, electron transport chain, energy conversion, oxygen, proton-motive force
Cytochrome c oxidases (Coxs) are the basic energy transducers in the respiratory chain of the majority of aerobic organisms. Coxs studied to date are redox-driven proton-pumping enzymes belonging to one of three subfamilies: A-, B-, and C-type oxidases. The C-type oxidases ( cbb ₃ cytochromes), which are widespread among pathogenic bacteria, are the least understood. In particular, the proton-pumping machinery of these Coxs has not yet been elucidated despite the availability of X-ray structure information. Here, we report the discovery of the first (to our knowledge) sodium-pumping Cox (Scox), a cbb ₃ cytochrome from the extremely alkaliphilic bacterium Thioalkalivibrio versutus . This finding offers clues to the previously unknown structure of the ion-pumping channel in the C-type Coxs and provides insight into the functional properties of this enzyme.