Crystallographic structure and functional implications of the nitrogenase molybdenum-iron protein from azotobacter vinelandii.

The crystal structure of the nitrogenase molybdenum–iron protein from Azotobacter vinelandii has been determined at 2.7 Å resolution. The α- and β-subunits in this α (2) β (2) tetramer have similar polypeptide folds. The FeMo-cofactor is completely encompassed by the α-subunit, whereas the P-cluster pair occurs at the interface between α- and β-subunits. Structural similarities are apparent between nitrogenase and other electron transfer systems, including hydrogenases and the photosynthetic reaction centre