1a9z: Difference between revisions

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OCA

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-[[Image:1a9z.gif|left|200px]]<br /><applet load="1a9z" size="450" color="white" frame="true" align="right" spinBox="true"
-caption="1a9z, resolution 1.9&Aring;" />
-'''UDP-GALACTOSE 4-EPIMERASE MUTANT S124A/Y149F COMPLEXED WITH UDP-GALACTOSE'''<br />
-==Overview==
+==UDP-GALACTOSE 4-EPIMERASE MUTANT S124A/Y149F COMPLEXED WITH UDP-GALACTOSE==
-UDP-galactose 4-epimerase catalyzes the interconversion of UDP-galactose, and UDP-glucose during normal galactose metabolism. Within recent years, the enzyme from Escherichia coli has been studied extensively by both, biochemical and X-ray crystallographic techniques. One of several key, features in the catalytic mechanism of the enzyme involves the putative, rotation of a 4'-ketopyranose intermediate within the active site region., The mode of binding of UDP-glucose to epimerase is well understood on the, basis of previous high-resolution X-ray crystallographic investigations, from this laboratory with an enzyme/NADH/UDP-glucose abortive complex., Attempts to prepare an enzyme/NADH/UDP-galactose abortive complex always, failed, however, in that UDP-glucose rather than UDP-galactose was, observed binding in the active site. In an effort to prepare an abortive, complex with UDP-galactose, a site-directed mutant protein was constructed, in which Ser 124 and Tyr 149, known to play critical roles in catalysis, were substituted with alanine and phenylalanine residues, respectively., With this double mutant it was possible to crystallize and solve the, three-dimensional structures of reduced epimerase in the presence of, UDP-glucose or UDP-galactose to high resolution. This study represents the, first direct observation of UDP-galactose binding to epimerase and lends, strong structural support for a catalytic mechanism in which there is free, rotation of a 4'-ketopyranose intermediate within the active site cleft of, the enzyme.
+<StructureSection load='1a9z' size='340' side='right'caption='[[1a9z]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
+== Structural highlights ==
+<table><tr><td colspan='2'>[[1a9z]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1A9Z OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1A9Z FirstGlance]. <br>
+</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.9&#8491;</td></tr>
+<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=NAD:NICOTINAMIDE-ADENINE-DINUCLEOTIDE'>NAD</scene>, <scene name='pdbligand=PGE:TRIETHYLENE+GLYCOL'>PGE</scene>, <scene name='pdbligand=UPG:URIDINE-5-DIPHOSPHATE-GLUCOSE'>UPG</scene></td></tr>
+<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1a9z FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1a9z OCA], [https://pdbe.org/1a9z PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1a9z RCSB], [https://www.ebi.ac.uk/pdbsum/1a9z PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1a9z ProSAT]</span></td></tr>
+</table>
+== Function ==
+[https://www.uniprot.org/uniprot/GALE_ECOLI GALE_ECOLI]
+== Evolutionary Conservation ==
+[[Image:Consurf_key_small.gif|200px|right]]
+Check<jmol>
+  <jmolCheckbox>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/a9/1a9z_consurf.spt"</scriptWhenChecked>
+    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
+    <text>to colour the structure by Evolutionary Conservation</text>
+  </jmolCheckbox>
+</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1a9z ConSurf].
+<div style="clear:both"></div>
-==About this Structure==
+==See Also==
-A9Z is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with NA, NAD, UPG and PGE as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/UDP-glucose_4-epimerase UDP-glucose 4-epimerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.1.3.2 5.1.3.2] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1A9Z OCA].
+*[[UDP-galactose 4-epimerase|UDP-galactose 4-epimerase]]
+__TOC__
-==Reference==
+</StructureSection>
-Dramatic differences in the binding of UDP-galactose and UDP-glucose to UDP-galactose 4-epimerase from Escherichia coli., Thoden JB, Holden HM, Biochemistry. 1998 Aug 18;37(33):11469-77. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=9708982 9708982]
 [[Category: Escherichia coli]]
-[[Category: Single protein]]
+[[Category: Large Structures]]
-[[Category: UDP-glucose 4-epimerase]]
+[[Category: Holden HM]]
-[[Category: Holden, H.M.]]
+[[Category: Thoden JB]]
-[[Category: Thoden, J.B.]]
-[[Category: NA]]
-[[Category: NAD]]
-[[Category: PGE]]
-[[Category: UPG]]
-[[Category: dehydrogenase]]
-[[Category: epimerase]]
-[[Category: galactose metabolism]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 10:42:40 2007''