How the [NiFe4S4] Cluster of CO Dehydrogenase Activates CO2 and NCO−

摘要: Ni,Fe-containing CO dehydrogenases (CODHs) use a [NiFe4S4] cluster, termed cluster C, to reversibly reduce CO2 with high turnover number. Binding Ni and Fe activates CO2, but current crystal structures have insufficient resolution analyze the geometry of bound reveal extent nature its activation. The CODH in complex isoelectronic inhibitor NCO(-) are reported at true atomic (dmin ≤1.1 A). Like is μ2,η(2) ligand acts as mechanism-based inhibitor. While has carboxylate group, transformed into carbamoyl thus indicating that both molecules undergo formal two-electron reduction after binding stabilized by substantial π backbonding. combination stable coordination Fe2 reductive activation basis for inhibition NCO(-).