title: The heme-copper oxidase superfamily shares a Zn2+-binding motif at the entrance to a proton pathway.
abstract: Heme-copper oxidases (HCuOs) catalyse the reduction of oxygen, using the liberated free energy to maintain a proton-motive force across the membrane. In the mitochondrial-like A-type HCuOs, binding of heavy metal ions at the surface of the protein inhibits proton transfer. In bacterial C-type oxidases, the entry point to the proton pathway is on an accessory subunit unrelated to any subunit in A-type HCuOs. Despite this, we show here that heavy metal ions such as Zn(2+) inhibit O2-reduction very similarly in C-type as in A-type HCuOs, and furthermore that the binding site shares the same Glu-His motif.
authors: Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden.
authors: Hyun Ju
authors: HJ
authors: Lee
authors: Pia
authors: P
authors: Ädelroth
mesh_terms: D020816:Amino Acid Motifs; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D004926:Escherichia coli / Q000235:genetics; D006418:Heme / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D008958:Models, Molecular; D005810:Multigene Family; D016297:Mutagenesis, Site-Directed; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D018892:Proton-Motive Force; D011522:Protons; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012242:Rhodobacter sphaeroides / Q000737:chemistry* / Q000201:enzymology; D013816:Thermodynamics; D015032:Zinc / Q000737:chemistry / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D011522:Protons; D011994:Recombinant Proteins; D006418:Heme; D010088:Oxidoreductases; C024748:copper oxidase; D015032:Zinc; D010100:Oxygen