TY - JOUR
T1 - The Rhodospirillum rubrum cytochrome bc1 complex
T2 - pep tide composition, prosthetic group content and quinone binding
AU - Kriauciunas, Aidas
AU - Yu, Linda
AU - Yu, Chang An
AU - Wynn, R. Max
AU - Knaff, David B.
N1 - Funding Information:
This research was supported in part by grants from the National Science Foundation (DMB-8806609 to D.B.K.) and National Institutes of Health (GM 30721 to C.-A.Y.). The authors would like to thank Dr. Nadia Gabellini for the generous gift of the Rieske iron-sulfur protein antibody and Drs. Nadia Gabellini, Fevzi Daldal, Antony Crofts, James Harman and Dan Robertson for helpful discussions.
PY - 1989/8
Y1 - 1989/8
N2 - A cytochrome bc1 complex, essentially free of bacteriochlorophyll, has been purified from the photosynthetic purple non-sulfur bacterium Rhodospirillum rubrum. The complex catalyzes electron flow from quinol to cytochrome c (turnover number = 75 s-1) that is inhibited by low concentrations of antimycin A and myxothiazol. The complex contains only three peptide subunits: cytochrome b (Mr = 35000); cytochrome c1 (Mr = 31000) and the Rieske iron-sulfur protein (Mr = 22400). Em values (pH 7.4) were measured for cytochrome c, (+ 320 mV) and the two hemes of cytochrome b (- 33 and -90 mV). Electron flow from quinol to cytochrome c is inhibited when the complex is pre-illuminated in the presence of a ubiquinone photoaffinity analog (azido-Q). During illumination, the azido-Q becomes covalently attached to the cytochrome b peptide and, to a lesser extent, to cytochrome c1.
AB - A cytochrome bc1 complex, essentially free of bacteriochlorophyll, has been purified from the photosynthetic purple non-sulfur bacterium Rhodospirillum rubrum. The complex catalyzes electron flow from quinol to cytochrome c (turnover number = 75 s-1) that is inhibited by low concentrations of antimycin A and myxothiazol. The complex contains only three peptide subunits: cytochrome b (Mr = 35000); cytochrome c1 (Mr = 31000) and the Rieske iron-sulfur protein (Mr = 22400). Em values (pH 7.4) were measured for cytochrome c, (+ 320 mV) and the two hemes of cytochrome b (- 33 and -90 mV). Electron flow from quinol to cytochrome c is inhibited when the complex is pre-illuminated in the presence of a ubiquinone photoaffinity analog (azido-Q). During illumination, the azido-Q becomes covalently attached to the cytochrome b peptide and, to a lesser extent, to cytochrome c1.
KW - (R. rubrum)
KW - Cytochrome bc complex
KW - Electron transport chain
KW - Purple bacteria
KW - Quinone binding
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U2 - 10.1016/S0005-2728(89)80190-2
DO - 10.1016/S0005-2728(89)80190-2
M3 - Article
C2 - 2548618
AN - SCOPUS:0024972981
VL - 976
SP - 70
EP - 76
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
SN - 0005-2728
IS - 1
ER -