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Publication Abstract from PubMed

The heme-copper oxidases (HCOs) accomplish the key event of aerobic respiration; they couple O2 reduction and transmembrane proton pumping. To gain new insights into the still enigmatic process, we structurally characterized a C-family HCO--essential for the pathogenicity of many bacteria--that differs from the two other HCO families, A and B, that have been structurally analyzed. The x-ray structure of the C-family cbb3 oxidase from Pseudomonas stutzeri at 3.2 angstrom resolution shows an electron supply system different from families A and B. Like family-B HCOs, C HCOs have only one pathway, which conducts protons via an alternative tyrosine-histidine cross-link. Structural differences around hemes b and b3 suggest a different redox-driven proton-pumping mechanism and provide clues to explain the higher activity of family-C HCOs at low oxygen concentrations.

The structure of cbb3 cytochrome oxidase provides insights into proton pumping.,Buschmann S, Warkentin E, Xie H, Langer JD, Ermler U, Michel H Science. 2010 Jul 16;329(5989):327-30. Epub 2010 Jun 24. PMID:20576851^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.