title: Structure of a multicopper oxidase from the hyperthermophilic archaeon Pyrobaculum aerophilum.
abstract: The crystal structure of an extremely thermostable multicopper oxidase (McoP) from the hyperthermophilic archaeon Pyrobaculum aerophilum was determined at a resolution of 2.0 Å. The overall fold was comprised of three cupredoxin-like domains and the main-chain coordinates of the enzyme were similar to those of multicopper oxidases from Escherichia coli (CueO) and Bacillus subtilis (CotA). However, there were clear topological differences around domain 3 between McoP and the other two enzymes: a methionine-rich helix in CueO and a protruding helix in CotA were not present in McoP. Instead, a large loop (PL-1) covered the T1 copper centre of McoP and a short α-helix in domain 3 extended near the N-terminal end of PL-1. In addition, the sizes of several surface loops in McoP were markedly smaller than the corresponding loops in CueO and CotA. Structural comparison revealed that the presence of extensive hydrophobic interactions and a smaller cavity volume are likely to be the main factors contributing to the hyperthermostability of McoP.
authors.affiliation: Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0795, Japan. sakuraba@ag.kagawa-u.ac.jp
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Sakuraba
authors.forename: Kohtaroh
authors.initials: K
authors.lastname: Koga
authors.forename: Kazunari
authors.initials: K
authors.lastname: Yoneda
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kashima
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Ohshima
mesh_terms: D000595:Amino Acid Sequence; D017124:Conserved Sequence; D003300:Copper / Q000737:chemistry* / Q000378:metabolism; D018360:Crystallography, X-Ray; D004795:Enzyme Stability; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000737:chemistry* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D041543:Pyrobaculum / Q000201:enzymology*; D016415:Sequence Alignment; D040681:Structural Homology, Protein
chemical_list: D003300:Copper; D010088:Oxidoreductases