2fyu: Difference between revisions
New page: left|200px<br /><applet load="2fyu" size="450" color="white" frame="true" align="right" spinBox="true" caption="2fyu, resolution 2.26Å" /> '''Crystal structure of... |
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[[Image:2fyu.gif|left|200px]]<br /><applet load="2fyu" size=" | [[Image:2fyu.gif|left|200px]]<br /><applet load="2fyu" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="2fyu, resolution 2.26Å" /> | caption="2fyu, resolution 2.26Å" /> | ||
'''Crystal structure of bovine heart mitochondrial bc1 with jg144 inhibitor'''<br /> | '''Crystal structure of bovine heart mitochondrial bc1 with jg144 inhibitor'''<br /> | ||
==Overview== | ==Overview== | ||
In the cytochrome bc(1) complex, the swivel motion of the iron-sulfur | In the cytochrome bc(1) complex, the swivel motion of the iron-sulfur protein (ISP) between two redox sites constitutes a key component of the mechanism that achieves the separation of the two electrons in a substrate molecule at the quinol oxidation (Q(o)) site. The question remaining is how the motion of ISP is controlled so that only one electron enters the thermodynamically favorable chain via ISP. An analysis of eight structures of mitochondrial bc(1) with bound Q(o) site inhibitors revealed that the presence of inhibitors causes a bidirectional repositioning of the cd1 helix in the cytochrome b subunit. As the cd1 helix forms a major part of the ISP binding crater, any positional shift of this helix modulates the ability of cytochrome b to bind ISP. The analysis also suggests a mechanism for reversal of the ISP fixation when the shape complementarity is significantly reduced after a positional reorientation of the reaction product quinone. The importance of shape complementarity in this mechanism was confirmed by functional studies of bc(1) mutants and by a structure determination of the bacterial form of bc(1). A mechanism for the high fidelity of the bifurcated electron transfer is proposed. | ||
==About this Structure== | ==About this Structure== | ||
2FYU is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with HEM, FDN and FES as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ubiquinol--cytochrome-c_reductase Ubiquinol--cytochrome-c reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.10.2.2 1.10.2.2] Full crystallographic information is available from [http:// | 2FYU is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with <scene name='pdbligand=HEM:'>HEM</scene>, <scene name='pdbligand=FDN:'>FDN</scene> and <scene name='pdbligand=FES:'>FES</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ubiquinol--cytochrome-c_reductase Ubiquinol--cytochrome-c reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.10.2.2 1.10.2.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2FYU OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: transmembrane helices]] | [[Category: transmembrane helices]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:26:29 2008'' | ||
Revision as of 18:26, 21 February 2008
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Crystal structure of bovine heart mitochondrial bc1 with jg144 inhibitor
OverviewOverview
In the cytochrome bc(1) complex, the swivel motion of the iron-sulfur protein (ISP) between two redox sites constitutes a key component of the mechanism that achieves the separation of the two electrons in a substrate molecule at the quinol oxidation (Q(o)) site. The question remaining is how the motion of ISP is controlled so that only one electron enters the thermodynamically favorable chain via ISP. An analysis of eight structures of mitochondrial bc(1) with bound Q(o) site inhibitors revealed that the presence of inhibitors causes a bidirectional repositioning of the cd1 helix in the cytochrome b subunit. As the cd1 helix forms a major part of the ISP binding crater, any positional shift of this helix modulates the ability of cytochrome b to bind ISP. The analysis also suggests a mechanism for reversal of the ISP fixation when the shape complementarity is significantly reduced after a positional reorientation of the reaction product quinone. The importance of shape complementarity in this mechanism was confirmed by functional studies of bc(1) mutants and by a structure determination of the bacterial form of bc(1). A mechanism for the high fidelity of the bifurcated electron transfer is proposed.
About this StructureAbout this Structure
2FYU is a Protein complex structure of sequences from Bos taurus with , and as ligands. Active as Ubiquinol--cytochrome-c reductase, with EC number 1.10.2.2 Full crystallographic information is available from OCA.
ReferenceReference
Surface-modulated motion switch: capture and release of iron-sulfur protein in the cytochrome bc1 complex., Esser L, Gong X, Yang S, Yu L, Yu CA, Xia D, Proc Natl Acad Sci U S A. 2006 Aug 29;103(35):13045-50. Epub 2006 Aug 21. PMID:16924113
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