title: Structure of cytochrome c6 from the red alga Porphyra yezoensis at 1. 57 A resolution.
abstract: The crystal structure of cytochrome c(6) from the red alga Porphyra yezoensis has been determined at 1.57 A resolution. The crystal is tetragonal and belongs to space group P4(3)2(1)2, with unit-cell parameters a = b = 49.26 (3), c = 83.45 (4) A and one molecule per asymmetric unit. The structure was solved by the molecular-replacement method and refined with X-PLOR to an R factor of 19.9% and a free R factor of 25.4%. The overall structure of cytochrome c(6) follows the topology of class I c-type cytochromes in which the heme prosthetic group covalently binds to Cys14 and Cys17, and the iron has an octahedral coordination with His18 and Met58 as the axial ligands. The sequence and the structure of the eukaryotic red algal cytochrome c(6) are very similar to those of a prokaryotic cyanobacterial cytochrome c(6) rather than those of eukaryotic green algal c(6) cytochromes.
authors.affiliation: Department of Biological Chemistry, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-8510, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Yamada
authors.forename: S Y
authors.initials: SY
authors.lastname: Park
authors.forename: H
authors.initials: H
authors.lastname: Shimizu
authors.forename: Y
authors.initials: Y
authors.lastname: Koshizuka
authors.forename: K
authors.initials: K
authors.lastname: Kadokura
authors.forename: T
authors.initials: T
authors.lastname: Satoh
authors.forename: K
authors.initials: K
authors.lastname: Suruga
authors.forename: M
authors.initials: M
authors.lastname: Ogawa
authors.forename: Y
authors.initials: Y
authors.lastname: Isogai
authors.forename: T
authors.initials: T
authors.lastname: Nishio
authors.forename: Y
authors.initials: Y
authors.lastname: Shiro
authors.forename: T
authors.initials: T
authors.lastname: Oku
mesh_terms: D000595:Amino Acid Sequence; D000460:Chlorophyta / Q000737:chemistry; D018360:Crystallography, X-Ray; D003580:Cytochromes / Q000737:chemistry* / Q000302:isolation & purification; D045348:Cytochromes f; D006418:Heme / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D000461:Rhodophyta / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid
chemical_list: D003580:Cytochromes; D006418:Heme; D045348:Cytochromes f