title: The CuA domain of Thermus thermophilus ba3-type cytochrome c oxidase at 1.6 A resolution.
abstract: The structure of the CuA-containing, extracellular domain of Thermus thermophilus ba3-type cytochrome c oxidase has been determined to 1.6 A resolution using multiple X-ray wavelength anomalous dispersion (MAD). The Cu2S2 cluster forms a planar rhombus with a copper-copper distance of 2.51 +/- 0.03 A. X-ray absorption fine-structure (EXAFS) studies show that this distance is unchanged by crystallization. The CuA center is asymmetrical; one copper is tetrahedrally coordinated to two bridging cysteine thiolates, one histidine nitrogen and one methionine sulfur, while the other is trigonally coordinated by the two cysteine thiolates and a histidine nitrogen. Combined sequence-structure alignment of amino acid sequences reveals conserved interactions between cytochrome c oxidase subunits I and II.
authors.affiliation: Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Williams
authors.forename: N J
authors.initials: NJ
authors.lastname: Blackburn
authors.forename: D
authors.initials: D
authors.lastname: Sanders
authors.forename: H
authors.initials: H
authors.lastname: Bellamy
authors.forename: E A
authors.initials: EA
authors.lastname: Stura
authors.forename: J A
authors.initials: JA
authors.lastname: Fee
authors.forename: D E
authors.initials: DE
authors.lastname: McRee
mesh_terms: D000595:Amino Acid Sequence; D001400:Azurin / Q000031:analogs & derivatives / Q000737:chemistry; D001665:Binding Sites; D017124:Conserved Sequence; D003300:Copper / Q000378:metabolism*; D003460:Crystallization; D018360:Crystallography, X-Ray; D003545:Cysteine / Q000378:metabolism; D003573:Cytochrome b Group / Q000737:chemistry* / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000737:chemistry* / Q000378:metabolism; D006639:Histidine / Q000378:metabolism; D008715:Methionine / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D016415:Sequence Alignment; D013455:Sulfur / Q000378:metabolism; D016963:Thermus thermophilus / Q000737:chemistry / Q000201:enzymology*; D015032:Zinc / Q000378:metabolism
chemical_list: D003573:Cytochrome b Group; C050107:cupredoxin; D001400:Azurin; D006639:Histidine; D013455:Sulfur; D003300:Copper; D008715:Methionine; C058557:cytochrome ba3; D003576:Electron Transport Complex IV; D015032:Zinc; D003545:Cysteine