FeMo cofactor maturation on NifEN
- Yilin Hu*,
- Mary C. Corbett†,
- Aaron W. Fay*,
- Jerome A. Webber*,
- Keith O. Hodgson†,‡,§,
- Britt Hedman‡,§, and
- Markus W. Ribbe*,§
- *Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900;
- †Department of Chemistry, Stanford University, Stanford, CA 94305; and
- ‡Stanford Synchrotron Radiation Laboratory, Stanford Linear Accellerator Center, Stanford University, 2575 Sand Hill Road, MS 69, Menlo Park, CA 94025-7015
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Edited by Douglas C. Rees, California Institute of Technology, Pasadena, CA, and approved May 10, 2006 (received for review March 31, 2006)
Abstract
FeMo cofactor (FeMoco) biosynthesis is one of the most complicated processes in metalloprotein biochemistry. Here we show that Mo and homocitrate are incorporated into the Fe/S core of the FeMoco precursor while it is bound to NifEN and that the resulting fully complemented, FeMoco-like cluster is transformed into a mature FeMoco upon transfer from NifEN to MoFe protein through direct protein–protein interaction. Our findings not only clarify the process of FeMoco maturation, but also provide useful insights into the other facets of nitrogenase chemistry.
Footnotes
- §To whom correspondence may be addressed. E-mail: mribbe{at}uci.edu, hogdson{at}ssrl.slac.stanford.edu, or hedman{at}ssrl.slac.stanford.edu
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Author contributions: Y.H., K.O.H., B.H., and M.W.R. designed research; Y.H., M.C.C., A.W.F., J.A.W., and M.W.R. performed research; Y.H., M.C.C., K.O.H., B.H., and M.W.R. analyzed data; and Y.H., M.C.C., K.O.H., B.H., and M.W.R. wrote the paper.
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The authors declare no conflict of interest.
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This article is a PNAS direct submission.
- Abbreviations:
- FeMoco,
- FeMo cofactor;
- EXAFS,
- extended x-ray absorption fine structure;
- IDS,
- indigo disulfonate
- © 2006 by The National Academy of Sciences of the USA
