Resonance Raman characterization of archaeal and bacterial Rieske protein variants with modified hydrogen bond network around the [2Fe-2S] center.

ABSTRACT: The rate of quinol oxidation by cytochrome bc(1)/b(6)f complex is in part associated with the redox potential (E(m)) of its Rieske [2Fe-2S] center, for which an approximate correlation with the number of hydrogen bonds to the cluster has been proposed. Here we report comparative resonance Raman (RR) characterization of bacterial and archaeal high-potential Rieske proteins and their site-directed variants with a modified hydrogen bond network around the cluster. Major differences among their RR spectra appear to be associated in part with the presence or absence of Tyr-156 (in the Rhodobacter sphaeroides numbering) near one of the Cys ligands to the cluster. Elimination of the hydrogen bond between the terminal cysteinyl sulfur ligand (S(t)) and Tyr-Oeta (as with the Y156W variant, which ha

SUBMITTER: Iwasaki T 

PROVIDER: S-EPMC2242589 | biostudies-literature | 2006 Aug

REPOSITORIES: biostudies-literature