title: Cytochrome aa(3) in Haloferax volcanii.
abstract: A cytochrome in an extremely halophilic archaeon, Haloferax volcanii, was purified to homogeneity. This protein displayed a redox difference spectrum that is characteristic of a-type cytochromes and a CN(-) complex spectrum that indicates the presence of heme a and heme a(3). This cytochrome aa(3) consisted of 44- and 35-kDa subunits. The amino acid sequence of the 44-kDa subunit was similar to that of the heme-copper oxidase subunit I, and critical amino acid residues for metal binding, such as histidines, were highly conserved. The reduced cytochrome c partially purified from the bacterial membrane fraction was oxidized by the cytochrome aa(3), providing physiological evidence for electron transfer from cytochrome c to cytochrome aa(3) in archaea.
authors.affiliation: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan. TanakaM@ninds.nih.gov
authors.forename: Mikiei
authors.initials: M
authors.lastname: Tanaka
authors.forename: Naohide
authors.initials: N
authors.lastname: Ogawa
authors.forename: Kunio
authors.initials: K
authors.lastname: Ihara
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Mukohata
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D003001:Cloning, Molecular; D003574:Cytochrome c Group / Q000302:isolation & purification; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D019766:Genes, Archaeal; D019622:Haloferax volcanii / Q000201:enzymology*; D006418:Heme / Q000031:analogs & derivatives* / Q000032:analysis; D021122:Protein Subunits; D013053:Spectrophotometry
chemical_list: D019843:Archaeal Proteins; D003574:Cytochrome c Group; D021122:Protein Subunits; C027728:heme a; D006418:Heme; D003576:Electron Transport Complex IV