Nuclear resonance vibrational spectroscopy and electron paramagnetic resonance spectroscopy of 57Fe-enriched [FeFe] hydrogenase indicate stepwise assembly of the H-cluster.

ABSTRACT: The [FeFe] hydrogenase from Clostridium pasteurianum (CpI) harbors four Fe-S clusters that facilitate the transfer of an electron to the H-cluster, a ligand-coordinated six-iron prosthetic group that catalyzes the redox interconversion of protons and H(2). Here, we have used (57)Fe nuclear resonance vibrational spectroscopy (NRVS) to study the iron centers in CpI, and we compare our data to that for a [4Fe-4S] ferredoxin as well as a model complex resembling the [2Fe](H) catalytic domain of the H-cluster. To enrich the hydrogenase with (57)Fe nuclei, we used cell-free methods to post-translationally mature the enzyme. Specifically, inactive CpI apoprotein with (56)Fe-labeled Fe-S clusters was activated in vitro using (57)Fe-enriched maturation proteins. This approach enabled us to selectiv

SUBMITTER: Kuchenreuther JM 

PROVIDER: S-EPMC3644562 | biostudies-literature | 2013 Feb

REPOSITORIES: biostudies-literature