2ibz
From Proteopedia
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Yeast Cytochrome BC1 Complex with Stigmatellin
Overview
We describe in detail the conformations of the inhibitor stigmatellin in its free form and bound to the ubiquinone-reducing (Q(B)) site of the reaction center and to the ubiquinol-oxidizing (Q(o)) site of the cytochrome bc(1) complex. We present here the first structures of a stereochemically correct stigmatellin in complexes with a bacterial reaction center and the yeast cytochrome bc1 complex. The conformations of the inhibitor bound to the two enzymes are not the same. We focus on the orientations of the stigmatellin side-chain relative to the chromone head group, and on the interaction of the stigmatellin side-chain with these membrane protein complexes. The different conformations of stigmatellin found illustrate the structural variability of the Q sites, which are affected by the same inhibitor. The free rotation about the chi1 dihedral angle is an essential factor for allowing stigmatellin to bind in both the reaction center and the cytochrome bc1 pocket.
About this Structure
2IBZ is a Protein complex structure of sequences from Mus musculus and Saccharomyces cerevisiae with , , and as ligands. Active as Ubiquinol--cytochrome-c reductase, with EC number 1.10.2.2 Full crystallographic information is available from OCA.
Reference
A comparison of stigmatellin conformations, free and bound to the photosynthetic reaction center and the cytochrome bc1 complex., Lancaster CR, Hunte C, Kelley J 3rd, Trumpower BL, Ditchfield R, J Mol Biol. 2007 Apr 20;368(1):197-208. Epub 2007 Feb 11. PMID:17337272
Page seeded by OCA on Thu Feb 21 17:51:02 2008
