Nitrile hydratase from Rhodococcus rhodochrous J1 contains a non-corrin cobalt ion with two sulfur ligands
- DuPont, Wilmington, DE (United States)
- Haverford College, PA (United States)
We present spectroscopic data that show that a nitrile hydratase from Rhodococcus rhodochrous J1 is the first reported example of a native protein that contains a non-corrin Co{sup 3+} ion with a mixed S and N(O) ligand field. The similarities of the pre-edge and EXAFS spectra suggest that the ligand environments of the metal ions in the cobalt- and the iron-containing nitrile hydratases are very similar. Low-spin six-coordinate CO{sup 3+} complexes show S {yields} Co{sup 3+} charge transfer transitions at approximately 280 nm. Although featureless in the visible region, the absorption spectrum of nitrile hydratase from R. rhodochrous J1 (data not shown) has a significant shoulder above 300 nm that we suggest may have S {yields} Co ligand-to-metal charge transfer character. The absence of coenzyme B{sub 12} in the enzyme is shown by the lack of corrin absorbance in the visible spectrum and by the strong similarity in metal sites in the iron- and cobalt-containing nitrile hydratases revealed by EXAFS. Although there are several naturally occurring non-corrin Co{sup 2+} enzymes, the nitrile hydratase from R. rhodochrous J1 is the first example, to our knowledge, of a native non-corrin Co{sup 3+} enzyme as well as of biological Co-S coordination. 28 refs., 3 figs.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 420826
- Journal Information:
- Journal of the American Chemical Society, Vol. 118, Issue 38; Other Information: PBD: 25 Sep 1996
- Country of Publication:
- United States
- Language:
- English
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