Q-band ENDOR spectra of the Rieske protein from Rhodobactor capsulatus ubiquinol-cytochrome c oxidoreductase show two histidines coordinated to the [2Fe-2S] cluster.
Electron nuclear double resonance (ENDOR) experiments were performed on 14N (natural abundance) and 15N-enriched iron-sulfur Rieske protein in the ubiquinol-cytochrome c2 oxidoreductase from Rhodobactor capsulatus. The experiments proved that two distinct nitrogenous ligands, histidines, are undoubtedly ligated to the Rieske [2Fe-2S] center. The calculations of hyperfine tensors give values similar but not identical to those of the Rieske-type cluster in phthalate dioxygenase of Pseudomonas cepacia and suggest a slightly different geometry of the iron-sulfur cluster in the two proteins.
Gurbiel
R J
RJ
Department of Chemistry, Northwestern University, Evanston, Illinois 60208.
Ohnishi
T
T
Robertson
D E
DE
Daldal
F
F
Hoffman
B M
BM
D000595:Amino Acid Sequence; D004578:Electron Spin Resonance Spectroscopy; D014450:Electron Transport Complex III / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry*; D007506:Iron-Sulfur Proteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000737:chemistry; D016354:Rhodobacter capsulatus / Q000201:enzymology*; D013050:Spectrometry, Fluorescence
D007506:Iron-Sulfur Proteins; C037989:Rieske iron-sulfur protein; D006639:Histidine; D014450:Electron Transport Complex III; D009584:Nitrogen