Mechanism and Assembly of Ni, Fe-Containing Carbon Monoxide Dehydrogenases

Carbon monoxide dehydrogenases catalyze the reversible oxidation of CO with water to CO2, two protons and two electrons, a central reaction of microorganisms using CO as a source of energy and in the autotrophic conversion of CO2 by several anaerobic microorganisms. Ni,Fe-containing carbon monoxide dehydrogenases catalyze this reaction at a complex Ni-, Fe- and S-containing metal cluster, whose assembly is dependent on ATPases. Within the last funding period we determined the structure of the carbon monoxide dehydrogenase with the active [NiFe4S4OHx]-cluster and analyzed the active site in complex with substrate CO2 and the inhibitor CN-. We could show that the ATPase CooC involved in the assembly of the Ni,Fecluster binds Ni2+ and that the Ni-binding site and the ATP-binding site communicate. Furthermore, we determined the crystal structure of CooC. In the next funding period we want to analyze different active and inactive states of the Ni,Fe-cluster and want to elucidate the role of the related ATPases CooC and AcsF in the assembly of the Ni,Fe-clusters of carbon monoxide dehydrogenases and acetyl-CoA synthases.