The relationship between structure and function for the sulfite reductases.
The six-electron reductions of sulfite to sulfide and nitrite to ammonia, fundamental to early and contemporary life, are catalyzed by diverse sulfite and nitrite reductases that share an unusual prosthetic assembly in their active centers, namely siroheme covalently linked to an Fe4S4 cluster. The recently determined crystallographic structure of the sulfite reductase hemoprotein from Escherichia coli complements extensive biochemical and spectroscopic studies in revealing structural features that are key for the catalytic mechanisms and in suggesting a common symmetric structural unit for this diverse family of enzymes.
Crane
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Department of Molecular Biology, Scripps Research Institute, La Jolla, CA 92037, USA. crane@scripps.edu
Getzoff
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D000595:Amino Acid Sequence; D001665:Binding Sites; D004789:Enzyme Activation; D004926:Escherichia coli / Q000201:enzymology; D006418:Heme / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009572:Nitrite Reductases / Q000737:chemistry / Q000145:classification / Q000378:metabolism; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000737:chemistry* / Q000145:classification / Q000378:metabolism*; D016415:Sequence Alignment; D013329:Structure-Activity Relationship
D007506:Iron-Sulfur Proteins; D006418:Heme; C009272:siroheme; D009572:Nitrite Reductases; D050862:Oxidoreductases Acting on Sulfur Group Donors