5KLI

Rhodobacter sphaeroides bc1 with stigmatellin and antimycin

Summary for 5KLI

• Entry DOI: 10.2210/pdb5kli/pdb
• Related: 5KKZ 5KLV
• Descriptor: Cytochrome b, FE2/S2 (INORGANIC) CLUSTER, Cytochrome c1, ... (10 entities in total)
• Functional Keywords: mitochondrial respiratory chain complex, cytochrome bc1, inhibitors, electron transfer, oxidoreductase
• Biological source: Rhodobacter sphaeroides; More
• Cellular location: Cell membrane; Multi-pass membrane protein: Q02761; Cell membrane ; Single-pass membrane protein : Q02760 Q02762
• Total number of polymer chains: 12
• Total formula weight: 413955.39

Authors

Xia, D.,Esser, L.,Zhou, F.,Tang, W.K.,Yu, C.A. (deposition date: 2016-06-24, release date: 2016-10-12, Last modification date: 2024-11-06)

Primary citation

Esser, L.,Zhou, F.,Zhou, Y.,Xiao, Y.,Tang, W.K.,Yu, C.A.,Qin, Z.,Xia, D.
Hydrogen Bonding to the Substrate Is Not Required for Rieske Iron-Sulfur Protein Docking to the Quinol Oxidation Site of Complex III.
J.Biol.Chem., 291:25019-25031, 2016

PubMed Abstract: Complex III or the cytochrome (cyt) bc complex constitutes an integral part of the respiratory chain of most aerobic organisms and of the photosynthetic apparatus of anoxygenic purple bacteria. The function of cyt bc is to couple the reaction of electron transfer from ubiquinol to cytochrome c to proton pumping across the membrane. Mechanistically, the electron transfer reaction requires docking of its Rieske iron-sulfur protein (ISP) subunit to the quinol oxidation site (Q) of the complex. Formation of an H-bond between the ISP and the bound substrate was proposed to mediate the docking. Here we show that the binding of oxazolidinedione-type inhibitors famoxadone, jg144, and fenamidone induces docking of the ISP to the Q site in the absence of the H-bond formation both in mitochondrial and bacterial cyt bc complexes, demonstrating that ISP docking is independent of the proposed direct ISP-inhibitor interaction. The binding of oxazolidinedione-type inhibitors to cyt bc of different species reveals a toxophore that appears to interact optimally with residues in the Q site. The effect of modifications or additions to the toxophore on the binding to cyt bc from different species could not be predicted from structure-based sequence alignments, as demonstrated by the altered binding mode of famoxadone to bacterial cyt bc.

PubMed: 27758861
DOI: 10.1074/jbc.M116.744391

Experimental method

X-RAY DIFFRACTION (2.996 Å)