Modeling the active sites of metalloenzymes. 4. Predictions of the unready states of [NiFe] Desulfovibrio gigas hydrogenase from density functional theory.
Density functional theory has been used to predict the structures of a variety of active site models for the unready states, Ni-A and Ni-SU, of the [NiFe] hydrogenase from Desulfovibrio gigas. By comparing available experimental results on Ni-A, Ni-SU, and Ni-SI with the computational results on these model complexes, we have been able to identify the most likely formulas and structures for the active sites of Ni-A and Ni-SU. Ni-A is predicted to be a Ni(III)-Fe(II) species with the bridging hydroxo ligand, rather than the expected oxo ligand, while Ni-SU is predicted to be a Ni(II)-Fe(II) species with a water molecule coordinated to the Fe center. Both have one of the terminal S atoms (cysteines) protonated.
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Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA.
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D001665:Binding Sites; D018360:Crystallography, X-Ray; D003901:Desulfovibrio / Q000201:enzymology*; D006864:Hydrogenase / Q000737:chemistry* / Q000378:metabolism*; D008667:Metalloproteins / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D011487:Protein Conformation
D008667:Metalloproteins; D006864:Hydrogenase