2nt9: Difference between revisions
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==Crystal structure of pectin methylesterase D178A mutant in complex with hexasaccharide IV== | |||
<StructureSection load='2nt9' size='340' side='right'caption='[[2nt9]], [[Resolution|resolution]] 1.90Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2nt9]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Dickeya_dadantii_3937 Dickeya dadantii 3937]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2NT9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2NT9 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]] 1.9Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ADA:ALPHA-D-GALACTOPYRANURONIC+ACID'>ADA</scene>, <scene name='pdbligand=M8C:METHYL+ALPHA-D-GALACTOPYRANURONATE'>M8C</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=2nt9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2nt9 OCA], [https://pdbe.org/2nt9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2nt9 RCSB], [https://www.ebi.ac.uk/pdbsum/2nt9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2nt9 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/PMEA_DICD3 PMEA_DICD3] Involved in maceration and soft-rotting of plant tissue. | |||
== 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/nt/2nt9_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=2nt9 ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
We provide a mechanism for the activity of pectin methylesterase (PME), the enzyme that catalyses the essential first step in bacterial invasion of plant tissues. The complexes formed in the crystal using specifically methylated pectins, together with kinetic measurements of directed mutants, provide clear insights at atomic resolution into the specificity and the processive action of the Erwinia chrysanthemi enzyme. Product complexes provide additional snapshots along the reaction coordinate. We previously revealed that PME is a novel aspartic-esterase possessing parallel beta-helix architecture and now show that the two conserved aspartates are the nucleophile and general acid-base in the mechanism, respectively. Other conserved residues at the catalytic centre are shown to be essential for substrate binding or transition state stabilisation. The preferential binding of methylated sugar residues upstream of the catalytic site, and demethylated residues downstream, drives the enzyme along the pectin molecule and accounts for the sequential pattern of demethylation produced by both bacterial and plant PMEs. | We provide a mechanism for the activity of pectin methylesterase (PME), the enzyme that catalyses the essential first step in bacterial invasion of plant tissues. The complexes formed in the crystal using specifically methylated pectins, together with kinetic measurements of directed mutants, provide clear insights at atomic resolution into the specificity and the processive action of the Erwinia chrysanthemi enzyme. Product complexes provide additional snapshots along the reaction coordinate. We previously revealed that PME is a novel aspartic-esterase possessing parallel beta-helix architecture and now show that the two conserved aspartates are the nucleophile and general acid-base in the mechanism, respectively. Other conserved residues at the catalytic centre are shown to be essential for substrate binding or transition state stabilisation. The preferential binding of methylated sugar residues upstream of the catalytic site, and demethylated residues downstream, drives the enzyme along the pectin molecule and accounts for the sequential pattern of demethylation produced by both bacterial and plant PMEs. | ||
Molecular basis of the activity of the phytopathogen pectin methylesterase.,Fries M, Ihrig J, Brocklehurst K, Shevchik VE, Pickersgill RW EMBO J. 2007 Sep 5;26(17):3879-87. Epub 2007 Aug 23. PMID:17717531<ref>PMID:17717531</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 2nt9" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Methylesterase 3D structures|Methylesterase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Dickeya dadantii 3937]] | |||
[[Category: Large Structures]] | |||
[[Category: Brocklehurst K]] | |||
[[Category: Fries M]] | |||
[[Category: Pickersgill RW]] | |||
[[Category: Shevchik VE]] | |||