1eex

<StructureSection load='1eex' size='340' side='right' caption='[[1eex]], [[Resolution|resolution]] 1.70&Aring;' scene=''>

<table><tr><td colspan='2'>[[1eex]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_oxytocus_perniciosus"_flugge_1886 "bacillus oxytocus perniciosus" flugge 1886]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EEX OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1EEX FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=COY:CO-(ADENIN-9-YL-PENTYL)-COBALAMIN'>COY</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=PGO:S-1,2-PROPANEDIOL'>PGO</scene></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Propanediol_dehydratase Propanediol dehydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.28 4.2.1.28] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1eex FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1eex OCA], [http://pdbe.org/1eex PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1eex RCSB], [http://www.ebi.ac.uk/pdbsum/1eex PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1eex ProSAT]</span></td></tr>

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== Publication Abstract from PubMed ==

BACKGROUND: Adenosylcobalamin (coenzyme B(12)) serves as a cofactor for enzymatic radical reactions. The adenosyl radical, a catalytic radical in these reactions, is formed by homolysis of the cobalt-carbon bond of the coenzyme, although the mechanism of cleavage of its organometallic bond remains unsolved. RESULTS: We determined the three-dimensional structures of diol dehydratase complexed with adeninylpentylcobalamin and with cyanocobalamin at 1.7 A and 1.9 A resolution, respectively, at cryogenic temperatures. In the adeninylpentylcobalamin complex, the adenine ring is bound parallel to the corrin ring as in the free form and methylmalonyl-CoA-mutase-bound coenzyme, but with the other side facing pyrrole ring C. All of its nitrogen atoms except for N(9) are hydrogen-bonded to mainchain amide oxygen and amide nitrogen atoms, a sidechain hydroxyl group, and a water molecule. As compared with the cyanocobalamin complex, the sidechain of Seralpha224 rotates by 120 degrees to hydrogen bond with N(3) of the adenine ring. CONCLUSIONS: The structure of the adenine-ring-binding site provides a molecular basis for the strict specificity of diol dehydratase for the coenzyme adenosyl group. The superimposition of the structure of the free coenzyme on that of enzyme-bound adeninylpentylcobalamin demonstrated that the tight enzyme-coenzyme interactions at both the cobalamin moiety and adenine ring of the adenosyl group would inevitably lead to cleavage of the cobalt-carbon bond. Rotation of the ribose moiety around the glycosidic linkage makes the 5'-carbon radical accessible to the hydrogen atom of the substrate to be abstracted.

How a protein generates a catalytic radical from coenzyme B(12): X-ray structure of a diol-dehydratase-adeninylpentylcobalamin complex.,Masuda J, Shibata N, Morimoto Y, Toraya T, Yasuoka N Structure. 2000 Jul 15;8(7):775-88. PMID:10903944<ref>PMID:10903944</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 1eex" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Bacillus oxytocus perniciosus flugge 1886]]

[[Category: Propanediol dehydratase]]

[[Category: Masuda, J]]

[[Category: Morimoto, Y]]

[[Category: Shibata, N]]

[[Category: Toraya, T]]

[[Category: Yasuoka, N]]

[[Category: Tim barrel]]