1kek: Difference between revisions
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New page: left|200px<br /><applet load="1kek" size="450" color="white" frame="true" align="right" spinBox="true" caption="1kek, resolution 1.90Å" /> '''Crystal Structure of... |
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[[Image:1kek.gif|left|200px]]<br /><applet load="1kek" size=" | [[Image:1kek.gif|left|200px]]<br /><applet load="1kek" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1kek, resolution 1.90Å" /> | caption="1kek, resolution 1.90Å" /> | ||
'''Crystal Structure of the Free Radical Intermediate of Pyruvate:Ferredoxin Oxidoreductase'''<br /> | '''Crystal Structure of the Free Radical Intermediate of Pyruvate:Ferredoxin Oxidoreductase'''<br /> | ||
==Overview== | ==Overview== | ||
In anaerobic organisms, the decarboxylation of pyruvate, a crucial | In anaerobic organisms, the decarboxylation of pyruvate, a crucial component of intermediary metabolism, is catalyzed by the metalloenzyme pyruvate: ferredoxin oxidoreductase (PFOR) resulting in the generation of low potential electrons and the subsequent acetylation of coenzyme A (CoA). PFOR is the only enzyme for which a stable acetyl thiamine diphosphate (ThDP)-based free radical reaction intermediate has been identified. The 1.87 A-resolution structure of the radical form of PFOR from Desulfovibrio africanus shows that, despite currently accepted ideas, the thiazole ring of the ThDP cofactor is markedly bent, indicating a drastic reduction of its aromaticity. In addition, the bond connecting the acetyl group to ThDP is unusually long, probably of the one-electron type already described for several cation radicals but not yet found in a biological system. Taken together, our data, along with evidence from the literature, suggest that acetyl-CoA synthesis by PFOR proceeds via a condensation mechanism involving acetyl (PFOR-based) and thiyl (CoA-based) radicals. | ||
==About this Structure== | ==About this Structure== | ||
1KEK is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Desulfovibrio_africanus Desulfovibrio africanus] with MG, CA, SF4, HTL and CO2 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Pyruvate_synthase Pyruvate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.2.7.1 1.2.7.1] Full crystallographic information is available from [http:// | 1KEK is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Desulfovibrio_africanus Desulfovibrio africanus] with <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=SF4:'>SF4</scene>, <scene name='pdbligand=HTL:'>HTL</scene> and <scene name='pdbligand=CO2:'>CO2</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Pyruvate_synthase Pyruvate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.2.7.1 1.2.7.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KEK OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Chabriere, E.]] | [[Category: Chabriere, E.]] | ||
[[Category: Charon, M | [[Category: Charon, M H.]] | ||
[[Category: Fontecilla-Camps, J | [[Category: Fontecilla-Camps, J C.]] | ||
[[Category: Guigliarelli, B.]] | [[Category: Guigliarelli, B.]] | ||
[[Category: Hatchikian, E | [[Category: Hatchikian, E C.]] | ||
[[Category: Vernede, X.]] | [[Category: Vernede, X.]] | ||
[[Category: CA]] | [[Category: CA]] | ||
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[[Category: homodimer]] | [[Category: homodimer]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:33:16 2008'' | ||
