3mhg: Difference between revisions
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[[Image: | ==Dihydroxyacetone phosphate carbanion intermediate in tagatose-1,6-bisphosphate aldolase from Streptococcus pyogenes== | ||
<StructureSection load='3mhg' size='340' side='right' caption='[[3mhg]], [[Resolution|resolution]] 1.92Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3mhg]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Streptococcus_pyogenes_serotype_m1 Streptococcus pyogenes serotype m1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3MHG OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3MHG FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=13P:1,3-DIHYDROXYACETONEPHOSPHATE'>13P</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></td></tr> | |||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3mhf|3mhf]]</td></tr> | |||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">lacD.2, lacD2, M5005_Spy1635, SPy_1919 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=301447 Streptococcus pyogenes serotype M1])</td></tr> | |||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Tagatose-bisphosphate_aldolase Tagatose-bisphosphate aldolase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.2.40 4.1.2.40] </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=3mhg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3mhg OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3mhg RCSB], [http://www.ebi.ac.uk/pdbsum/3mhg PDBsum]</span></td></tr> | |||
</table> | |||
== 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/mh/3mhg_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/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Tagatose-1,6-bisphosphate aldolase from Streptococcus pyogenes is a class I aldolase that exhibits a remarkable lack of chiral discrimination with respect to the configuration of hydroxyl groups at both C3 and C4 positions. The enzyme catalyzes the reversible cleavage of four diastereoisomers (fructose 1,6-bisphosphate (FBP), psicose 1,6-bisphosphate, sorbose 1,6-bisphosphate, and tagatose 1,6-bisphosphate) to dihydroxyacetone phosphate (DHAP) and d-glyceraldehyde 3-phosphate with high catalytic efficiency. To investigate its enzymatic mechanism, high resolution crystal structures were determined of both native enzyme and native enzyme in complex with dihydroxyacetone-P. The electron density map revealed a (alpha/beta)(8) fold in each dimeric subunit. Flash-cooled crystals of native enzyme soaked with dihydroxyacetone phosphate trapped a covalent intermediate with carbanionic character at Lys(205), different from the enamine mesomer bound in stereospecific class I FBP aldolase. Structural analysis indicates extensive active site conservation with respect to class I FBP aldolases, including conserved conformational responses to DHAP binding and conserved stereospecific proton transfer at the DHAP C3 carbon mediated by a proximal water molecule. Exchange reactions with tritiated water and tritium-labeled DHAP at C3 hydrogen were carried out in both solution and crystalline state to assess stereochemical control at C3. The kinetic studies show labeling at both pro-R and pro-S C3 positions of DHAP yet detritiation only at the C3 pro-S-labeled position. Detritiation of the C3 pro-R label was not detected and is consistent with preferential cis-trans isomerism about the C2-C3 bond in the carbanion as the mechanism responsible for C3 epimerization in tagatose-1,6-bisphosphate aldolase. | |||
Structure of a class I tagatose-1,6-bisphosphate aldolase: investigation into an apparent loss of stereospecificity.,LowKam C, Liotard B, Sygusch J J Biol Chem. 2010 Jul 2;285(27):21143-52. Epub 2010 Apr 28. PMID:20427286<ref>PMID:20427286</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Aldolase|Aldolase]] | *[[Aldolase|Aldolase]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Streptococcus pyogenes serotype m1]] | [[Category: Streptococcus pyogenes serotype m1]] | ||
[[Category: Tagatose-bisphosphate aldolase]] | [[Category: Tagatose-bisphosphate aldolase]] | ||
[[Category: Liotard, B | [[Category: Liotard, B]] | ||
[[Category: LowKam, C | [[Category: LowKam, C]] | ||
[[Category: Beta barrel]] | [[Category: Beta barrel]] | ||
[[Category: Carbanion]] | [[Category: Carbanion]] | ||
Revision as of 11:43, 9 December 2014
Dihydroxyacetone phosphate carbanion intermediate in tagatose-1,6-bisphosphate aldolase from Streptococcus pyogenesDihydroxyacetone phosphate carbanion intermediate in tagatose-1,6-bisphosphate aldolase from Streptococcus pyogenes
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedTagatose-1,6-bisphosphate aldolase from Streptococcus pyogenes is a class I aldolase that exhibits a remarkable lack of chiral discrimination with respect to the configuration of hydroxyl groups at both C3 and C4 positions. The enzyme catalyzes the reversible cleavage of four diastereoisomers (fructose 1,6-bisphosphate (FBP), psicose 1,6-bisphosphate, sorbose 1,6-bisphosphate, and tagatose 1,6-bisphosphate) to dihydroxyacetone phosphate (DHAP) and d-glyceraldehyde 3-phosphate with high catalytic efficiency. To investigate its enzymatic mechanism, high resolution crystal structures were determined of both native enzyme and native enzyme in complex with dihydroxyacetone-P. The electron density map revealed a (alpha/beta)(8) fold in each dimeric subunit. Flash-cooled crystals of native enzyme soaked with dihydroxyacetone phosphate trapped a covalent intermediate with carbanionic character at Lys(205), different from the enamine mesomer bound in stereospecific class I FBP aldolase. Structural analysis indicates extensive active site conservation with respect to class I FBP aldolases, including conserved conformational responses to DHAP binding and conserved stereospecific proton transfer at the DHAP C3 carbon mediated by a proximal water molecule. Exchange reactions with tritiated water and tritium-labeled DHAP at C3 hydrogen were carried out in both solution and crystalline state to assess stereochemical control at C3. The kinetic studies show labeling at both pro-R and pro-S C3 positions of DHAP yet detritiation only at the C3 pro-S-labeled position. Detritiation of the C3 pro-R label was not detected and is consistent with preferential cis-trans isomerism about the C2-C3 bond in the carbanion as the mechanism responsible for C3 epimerization in tagatose-1,6-bisphosphate aldolase. Structure of a class I tagatose-1,6-bisphosphate aldolase: investigation into an apparent loss of stereospecificity.,LowKam C, Liotard B, Sygusch J J Biol Chem. 2010 Jul 2;285(27):21143-52. Epub 2010 Apr 28. PMID:20427286[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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