physiological function |
substrate binding reorders the conformation of apo-Met6p to facilitate a direct SN2-type methylation reaction. The closed active site desolvates the active site save one water that serves as a conduit from His707 to protonate the tetrahydrofolate N5. Oscillations around the Zn cluster allow the thiolate to attack the methyl group and the protonated tetrahydrofolate is already activated as a reasonable leaving group. The transition state is likely to be a classic pyramidal structure with 3 methyl hydrogens in a plane and the incoming thiolate and departing tetrahydrofolate amine as axial ligands |
Candida albicans |