title: The topology of CuA in relation to the other metal centres in cytochrome-c oxidase of Saccharomyces cerevisiae as determined by analysis of second-site reversions.
abstract: Second-site revertants were selected from a respiratory-deficient mutant carrying the mutation D369N located in a loop between helices IX and X close to H376 and H378, the proposed ligands of haem a3 and haem a, respectively. A reversion was observed in subunit II, in the vicinity of the CuA ligands. This same reversion compensates the subunit I deficiency mutation, S140L, assumed to be near H62, the second putative histidine ligand to haem a. These data enable us to propose a three-dimensional topology in which CuA in subunit II is located on top of the Positive-side of subunit I and in proximity to all three of its metal centres.
mesh_terms: D001665:Binding Sites; D003300:Copper / Q000737:chemistry*; D003576:Electron Transport Complex IV / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D008024:Ligands; D008928:Mitochondria / Q000201:enzymology*; D009154:Mutation; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013489:Suppression, Genetic / Q000235:genetics
chemical_list: D008024:Ligands; D003300:Copper; D003576:Electron Transport Complex IV