Evidence for selenocysteine coordination to the active site nickel in the [NiFeSe]hydrogenases from Desulfovibrio baculatus,
Eidsness, M. K., Scott R. A., Prickril B. C., Dervartanian D. V., Legall J., Moura I., Moura J. J., and Peck, H. D. Jr.
, Proc Natl Acad Sci U S A, Jan, Volume 86, Number 1, p.147-51, (1989)
AbstractNi and Se x-ray absorption spectroscopic studies of the [NiFeSe]hydrogenases from Desulfovibrio baculatus are described. The Ni site geometry is pseudo-octahedral with a coordinating ligand composition of 3-4 (N,O) at 2.06 A, 1-2 (S,Cl) at 2.17 A, and 1 Se at 2.44 A. The Se coordination environment consists of 1 C at 2.0 A and a heavy scatterer M (M = Ni or Fe) at approximately 2.4 A. These results are interpreted in terms of a selenocysteine residue coordinated to the Ni site. The possible role of the Ni-Se site in the catalytic activation of H2 is discussed.
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