title: Analysis of structural MtrC models based on homology with the crystal structure of MtrF.
abstract: The outer-membrane decahaem cytochrome MtrC is part of the transmembrane MtrCAB complex required for mineral respiration by Shewanella oneidensis. MtrC has significant sequence similarity to the paralogous decahaem cytochrome MtrF, which has been structurally solved through X-ray crystallography. This now allows for homology-based models of MtrC to be generated. The structure of these MtrC homology models contain ten bis-histidine-co-ordinated c-type haems arranged in a staggered cross through a four-domain structure. This model is consistent with current spectroscopic data and shows that the areas around haem 5 and haem 10, at the termini of an octahaem chain, are likely to have functions similar to those of the corresponding haems in MtrF. The electrostatic surfaces around haem 7, close to the β-barrels, are different in MtrF and MtrC, indicating that these haems may have different potentials and interact with substrates differently.
authors.affiliation: Centre for Molecular and Structural Biochemistry, School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
authors.forename: Marcus J
authors.initials: MJ
authors.lastname: Edwards
authors.forename: James K
authors.initials: JK
authors.lastname: Fredrickson
authors.forename: John M
authors.initials: JM
authors.lastname: Zachara
authors.forename: David J
authors.initials: DJ
authors.lastname: Richardson
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Clarke
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D003574:Cytochrome c Group / Q000737:chemistry*; D006418:Heme / Q000737:chemistry; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D020592:Shewanella; D040681:Structural Homology, Protein
chemical_list: D003574:Cytochrome c Group; D006418:Heme; C433527:MtrC protein, Shewanella