Cofactor composition and function of a H2-sensing regulatory hydrogenase as revealed by Mossbauer and EPR spectroscopy.

ABSTRACT: The regulatory hydrogenase (RH) from Ralstonia eutropha H16 acts as a sensor for the detection of environmental H2 and regulates gene expression related to hydrogenase-mediated cellular metabolism. In marked contrast to prototypical energy-converting [NiFe] hydrogenases, the RH is apparently insensitive to inhibition by O2 and CO. While the physiological function of regulatory hydrogenases is well established, little is known about the redox cycling of the [NiFe] center and the nature of the iron-sulfur (FeS) clusters acting as electron relay. The absence of any FeS cluster signals in EPR had been attributed to their particular nature, whereas the observation of essentially only two active site redox states, namely Ni-SI and Ni-C, invoked a different operant mechanism. In the present work,

SUBMITTER: Roncaroli F 

PROVIDER: S-EPMC5665086 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature