How many metals does it take to fix N2? A mechanistic overview of biological nitrogen fixation
- *Department of Biochemistry, University of Minnesota, Minneapolis, MN 55455; and
- ‡Division of Chemistry and Chemical Engineering, 114-96, Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125
-
Edited by Richard R. Schrock, Massachusetts Institute of Technology, Cambridge, MA, and approved June 28, 2006 (received for review May 19, 2006)
Abstract
During the process of biological nitrogen fixation, the enzyme nitrogenase catalyzes the ATP-dependent reduction of dinitrogen to ammonia. Nitrogenase consists of two component metalloproteins, the iron (Fe) protein and the molybdenum-iron (MoFe) protein; the Fe protein mediates the coupling of ATP hydrolysis to interprotein electron transfer, whereas the active site of the MoFe protein contains the polynuclear FeMo cofactor, a species composed of seven iron atoms, one molybdenum atom, nine sulfur atoms, an interstitial light atom, and one homocitrate molecule. This Perspective provides an overview of biological nitrogen fixation and introduces three contributions to this special feature that address central aspects of the mechanism and assembly of nitrogenase.
Footnotes
- †To whom correspondence may be addressed. E-mail: howar001{at}umn.edu or dcrees{at}caltech.edu
-
Author contributions: J.B.H. and D.C.R. wrote the paper.
-
The authors declare no conflict of interest.
-
This article is a PNAS direct submission.
- © 2006 by The National Academy of Sciences of the USA
