Nitrogenase: Difference between revisions

Before this crystal structure showing the complete nitrogenase complex was solved, crystal structures of the Fe and FeMo proteins had been solved, but the mechanisms of ATP hydrolysis and electron transfer were still unknown. In this structure, as indicated in the figure above, the two subunits of the Fe protein were observed to have swung closer together. This movement results from Fe protein binding to FeMo protein. Focusing in on the <scene name='Sandbox_10/1n2c_atp/3'>ATP binding pocket</scene> discussed above, especially on the <scene name='Sandbox_10/1n2c_atp_lys_10/1'>AlF4-</scene> that is an analog for the negatively charged planar transition state reveals that there are several positive charges in this vicinity that stabilize the transition state. Importantly, Lys 10 from the opposite subunit is an important source of stabilizing positive charge. Only in this structure where the two subunits have swung closer together is this residue in position to help catalyze the hydrolysis of the terminal phosphate of ATP.