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Biogenesis of the H‐cluster of the [FeFe]‐hydrogenase
Author(s) -
Broderick Joan B.,
Shepard Eric M.,
Duffus Benjamin R.,
Ghose Shourjo,
Joshi Neelambari,
Boyd Eric S.,
Peters John W.
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.98.2
Subject(s) - hydrogenase , chemistry , ligand (biochemistry) , biogenesis , electron paramagnetic resonance , cluster (spacecraft) , carbon monoxide dehydrogenase , iron–sulfur cluster , cyanide , stereochemistry , metalloprotein , carbon monoxide , enzyme , catalysis , inorganic chemistry , organic chemistry , biochemistry , receptor , physics , nuclear magnetic resonance , computer science , programming language , gene
The organometallic H‐cluster at the active site of [FeFe]‐hydrogenase consists of a [4Fe‐4S] cluster bridged to a 2Fe subcluster that is further coordinated by cyanide, carbon monoxide, and a nonprotein dithiolate ligand. Biosynthesis of this cluster requires three accessory proteins, two of which (HydE and HydG) are radical S‐adenosylmethionine (radical SAM) enzymes. The third, HydF, is a GTPase that binds iron‐sulfur clusters. EPR and FTIR spectroscopic studies have revealed that HydE and HydG serve to synthesize a CO and CN − ligated precursor on HydF that is ultimately transferred to the hydrogenase to effect activation. HydG has been shown to synthesize CO and CN − ligands from tyrosine using radical SAM chemistry. HydE is thought to synthesize the dithiolate ligand of the H‐cluster. Together, these results point to a mechanism for H‐cluster assembly in which radical SAM chemistry is utilized to modify standard iron‐sulfur clusters produced by the ISC machinery to generate the unique organometallic H‐cluster. This work has been supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Science, Office of Science, U.S. Department of Energy.