Modeling a central ligand in the nitrogenase FeMo cofactor

J Am Chem Soc. 2003 Feb 12;125(6):1466-7. doi: 10.1021/ja029041g.

Abstract

In very recent work by Einsle et al. (Science 2002, 297, 1696), a new X-ray crystallographic structure of the FeMo cofactor of nitrogenase with a central ligand was presented. The central ligand is a light atom (N, O, or C), and Einsle et al. suggest that it is nitrogen. We present density functional calculations on the FeMo cofactor, and we investigate N, O, and C as central ligands. We show that both N and O lead to energetically stable FeMo cofactor structures, whereas C is energetically unfavorable. By comparison of bond geometries with the crystallographically determined values, we show that the central ligand is most likely nitrogen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ligands
  • Models, Molecular
  • Molybdoferredoxin / chemistry*
  • Molybdoferredoxin / metabolism
  • Nitrogenase / chemistry*
  • Nitrogenase / metabolism
  • Protein Conformation
  • Thermodynamics

Substances

  • Ligands
  • Molybdoferredoxin
  • Nitrogenase