Structure and mechanism of the flavocytochrome c fumarate reductase of Shewanella putrefaciens MR-1.
Fumarate respiration is one of the most widespread types of anaerobic respiration. The soluble fumarate reductase of Shewanella putrefaciens MR-1 is a periplasmic tetraheme flavocytochrome c. The crystal structures of the enzyme were solved to 2.9 A for the uncomplexed form and to 2.8 A and 2.5 A for the fumarate and the succinate-bound protein, respectively. The structures reveal a flexible capping domain linked to the FAD-binding domain. A catalytic mechanism for fumarate reduction based on the structure of the complexed protein is proposed. The mechanism for the reverse reaction is a model for the homologous succinate dehydrogenase (complex II) of the respiratory chain. In flavocytochrome c fumarate reductase, all redox centers are in van der Waals contact with one another, thus providing an efficient conduit of electrons from the hemes via the FAD to fumarate.
Leys
D
D
Laboratory of Protein Biochemistry and Protein Engineering, Department of Biochemistry, Physiology and Microbiology, K.L. Ledeganckstraat 35, 9000 Gent, Belgium.
Tsapin
A S
AS
Nealson
K H
KH
Meyer
T E
TE
Cusanovich
M A
MA
Van Beeumen
J J
JJ
D000594:Amino Acid Oxidoreductases / Q000737:chemistry; D000595:Amino Acid Sequence; D001665:Binding Sites; D020134:Catalytic Domain; D003460:Crystallization; D018360:Crystallography, X-Ray; D003574:Cytochrome c Group / Q000737:chemistry* / Q000378:metabolism*; D004583:Electrons; D004926:Escherichia coli / Q000201:enzymology; D029968:Escherichia coli Proteins; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D005650:Fumarates / Q000737:chemistry / Q000378:metabolism; D006418:Heme / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry* / Q000378:metabolism*; D017510:Protein Folding; D017433:Protein Structure, Secondary; D020614:Shewanella putrefaciens / Q000201:enzymology*; D013385:Succinate Dehydrogenase / Q000737:chemistry* / Q000378:metabolism*; D019802:Succinic Acid / Q000737:chemistry / Q000378:metabolism
D003574:Cytochrome c Group; D029968:Escherichia coli Proteins; D005650:Fumarates; D005182:Flavin-Adenine Dinucleotide; D006418:Heme; C032005:fumaric acid; D019802:Succinic Acid; D010088:Oxidoreductases; D013385:Succinate Dehydrogenase; D000594:Amino Acid Oxidoreductases; C031955:L-aspartate oxidase, E coli; C064500:flavocytochrome c sulfide dehydrogenase