1. N 2 + 16MgATP 2- + 8e - + 8H + → 2NH 3 + 16MgADP - + 16H 2 PO 4 - + H 2

2. Complex of the nitrogenase proteins stabilized by ADP-AIF4− Howard J. B., Rees D. C. PNAS 2006;103:17088-17093 ©2006 by National Academy of Sciences

3. Ball-and-stick representation of the nitrogenase metalloclusters Howard J. B., Rees D. C. PNAS 2006;103:17088-17093 ©2006 by National Academy of Sciences

4. A view of the FeMo cofactor highlighting Fe atoms 2, 3, 6, and 7 (numbering from Protein Data Bank ID code 1M1N), along with MoFe protein amino acids ligands ( α-275Cys and α-442His) and the side chains of α-195His and α-70Val Barney B. M. et.al. PNAS 2006;103:17113-17118 ©2006 by National Academy of Sciences

5. Chatt-Type Mechanism for Single Site Catalysis N 2 + 6H + + 6e - → 2NH 3

6. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1859894 Proc Natl Acad Sci U S A. 2006 November 14; 103(46): 17088–17093. How many metals does it take to fix N 2 ? A mechanistic overview of biological nitrogen fixation James B. Howard *† and Douglas C. Rees †‡ *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

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