Heterodisulfide reductase from methanogenic archaea: a new catalytic role for an iron-sulfur cluster.
Heterodisulfide reductase (HDR) from methanogenic archaea is an iron-sulfur protein that catalyzes reversible reduction of the heterodisulfide (CoM-S-S-CoB) of the methanogenic thiol-coenzymes, coenzyme M (CoM-SH) and coenzyme B (CoB-SH). Via the characterization of a paramagnetic reaction intermediate generated upon oxidation of the enzyme in the presence of coenzyme M, the enzyme was shown to contain a [4Fe-4S] cluster in its active site that catalyzes reduction of the disulfide substrate in two one-electron reduction steps. The formal thiyl radical generated by the initial one-electron reduction of the disulfide is stabilized via reduction and coordination of the resultant thiol to the [4Fe-4S] cluster.
Hedderich
Reiner
R
Max-Planck-Institute for Terrestrial Microbiology, Karl-von-Frisch Strasse, D-35043 Marburg, Germany. hedderic@staff.uni-marburg.de
Hamann
Nils
N
Bennati
Marina
M
D001665:Binding Sites; D002384:Catalysis; D019605:Euryarchaeota / Q000201:enzymology*; D007506:Iron-Sulfur Proteins / Q000737:chemistry*; D017013:Methanobacteriaceae / Q000201:enzymology; D017021:Methanosarcina barkeri / Q000201:enzymology; D010088:Oxidoreductases / Q000737:chemistry* / Q000235:genetics; D021122:Protein Subunits / Q000737:chemistry; D013057:Spectrum Analysis
D007506:Iron-Sulfur Proteins; D021122:Protein Subunits; D010088:Oxidoreductases; C087171:heterodisulfide reductase