Octaheme tetrathionate reductase is a respiratory enzyme with novel heme ligation.
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.
Mowat
Christopher G
CG
Institute of Cell and Molecular Biology, School of Biological Sciences, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JR, UK.
Rothery
Emma
E
Miles
Caroline S
CS
McIver
Lisa
L
Doherty
Mary K
MK
Drewette
Katy
K
Taylor
Paul
P
Walkinshaw
Malcolm D
MD
Chapman
Stephen K
SK
Reid
Graeme A
GA
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*
D006418:Heme; D010088:Oxidoreductases; C022727:tetrathionate reductase