title: Octaheme tetrathionate reductase is a respiratory enzyme with novel heme ligation.
abstract: We have isolated a soluble cytochrome from Shewanella oneidensis that contains eight covalently attached heme groups and determined its crystal structure. One of these hemes exhibits novel ligation of the iron atom by the epsilon-amino group of a lysine residue, despite its attachment via a typical CXXCH motif. This heme is most likely the active site for tetrathionate reduction, a reaction catalyzed efficiently by this enzyme.
authors.affiliation: Institute of Cell and Molecular Biology, School of Biological Sciences, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JR, UK.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Mowat
authors.forename: Emma
authors.initials: E
authors.lastname: Rothery
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Miles
authors.forename: Lisa
authors.initials: L
authors.lastname: McIver
authors.forename: Mary K
authors.initials: MK
authors.lastname: Doherty
authors.forename: Katy
authors.initials: K
authors.lastname: Drewette
authors.forename: Paul
authors.initials: P
authors.lastname: Taylor
authors.forename: Malcolm D
authors.initials: MD
authors.lastname: Walkinshaw
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Chapman
authors.forename: Graeme A
authors.initials: GA
authors.lastname: Reid
mesh_terms: D001665:Binding Sites; D002384:Catalysis; D006418:Heme / Q000378:metabolism; D008958:Models, Molecular; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D011487:Protein Conformation; D020592:Shewanella / Q000201:enzymology*
chemical_list: D006418:Heme; D010088:Oxidoreductases; C022727:tetrathionate reductase