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The structure of cbb3 cytochrome oxidase provides insights into proton pumping
The heme-copper-oxidases (HCOs) accomplish the key event of aerobic respiration as they couple O2 reduction and transmembrane proton pumping. Hartmut Michel and colleagues structurally characterized a C-family HCO (essential for the pathogenicity of many bacteria) to gain new insights into this still enigmatic process. The x-ray structure of the C-family cbb3 oxidase the bacterium Pseudomonas stutzeri at 3.2 Å resolution shows an electron supply system different from that of the A and B families, as the team reported recently in the journal Science. Like family B HCOs, C HCOs have only one pathway, which conducts protons via an alternative tyrosine-histidine crosslink. 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. More ...
Contact: Hartmut Michel, Max-Planck-Institut für Biophysik, Max-von-Laue-Straße 3, 60438 Frankfurt/Main, Germany, hartmut.michel@mpibp-frankfurt.mpg.de
Full reference: Sabine Buschmann, Eberhard Warkentin, Hao Xie, Julian D. Langer, Ulrich Ermler, Hartmut Michel. 2010. The Structure of cbb3 Cytochrome Oxidase Provides Insights into Proton Pumping. Science. Published online 24 June 2010. DOI: 10.1126/science.1187303.