5kva: Difference between revisions

Line 1:

~~'''Unreleased structure'''~~

~~The entry~~ 5kva is ~~ON HOLD~~

==Crystal Structure of sorghum caffeoyl-CoA O-methyltransferase (CCoAOMT)==

== Structural highlights ==

<table><tr><td colspan='2'>[[5kva]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5KVA OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5KVA FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=SAM:S-ADENOSYLMETHIONINE'>SAM</scene></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=5kva FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5kva OCA], [http://pdbe.org/5kva PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5kva RCSB], [http://www.ebi.ac.uk/pdbsum/5kva PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5kva ProSAT]</span></td></tr>

</table>

== Publication Abstract from PubMed ==

Caffeoyl-CoA 3-O-methyltransferase (CCoAOMT) is an S-adenosyl methionine (SAM)-dependent O-methyltransferase responsible for methylation of the meta-hydroxyl group of caffeoyl-CoA, on the pathway to monolignols with their ring methoxylation status characteristic of guaiacyl or syringyl units in lignin. In order to better understand the unique class of type-2 O-methyltransferases from monocots, we have characterized CCoAOMT from sorghum (Sorghum bicolor) (SbCCoAOMT), including the SAM binary complex crystal structure, steady state enzyme kinetics, isothermal titration calorimetry (ITC), inductively coupled plasma-optical emission spectroscopy (ICP-OES) and molecular docking. Key amino acid residues were validated with site-directed mutagenesis. ITC data indicated a sequential binding mechanism for SbCCoAOMT, wherein SAM binds prior to caffeoyl-CoA, and the enzyme showed allosteric behavior with respect to it. 5-Hydroxyferuloyl-CoA was not a substrate for SbCCoAOMT. We propose a catalytic mechanism in which Lys180 acts as a catalytic base and deprotonates the reactive hydroxyl group of caffeoyl-CoA. This deprotonation is facilitated by the coordination of the reactive hydroxyl group by Ca2+ in the active site, lowering the pKa of the 3'-OH group. Collectively, these data give a new perspective on the catalytic mechanism of CCoAOMTs and provide a basis for the functional diversity exhibited by type-2 plant OMTs that contain a unique insertion loop (residues 208-231) conferring affinity for phenylpropanoid-CoA thioesters.

~~Authors~~:

Determination of the structure and catalytic mechanism of Sorghum bicolor caffeoyl-CoA O-methyltransferase.,Walker AM, Sattler SA, Regner MR, Jones JP, Ralph J, Vermerris W, Sattler SE, Kang C Plant Physiol. 2016 Jul 25. pii: pp.00845.2016. PMID:27457122<ref>PMID:27457122</ref>

~~Description~~:

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

[[Category: ~~Unreleased Structures~~]]

</div>

== References ==

__TOC__

</StructureSection>

[[Category: Jones, J P]]

[[Category: Kang, C]]

[[Category: Ralph, J]]

[[Category: Regner, M]]

[[Category: Sattler, S A]]

[[Category: Sattler, S E]]

[[Category: Vermerris, W]]

[[Category: Walker, A M]]

[[Category: Caffeoyl-coa o-methyltransferase]]

[[Category: Ccoaomt]]

[[Category: Ccomt omt]]

[[Category: Coenzyme some]]

[[Category: Methyltransferase]]

[[Category: Sam o-methyltransferase]]

[[Category: Sbccoaomt]]

[[Category: Transferase]]

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@@ Line 1: / Line 1: @@
-'''Unreleased structure'''
-The entry 5kva is ON HOLD
+==Crystal Structure of sorghum caffeoyl-CoA O-methyltransferase (CCoAOMT)==
+<StructureSection load='5kva' size='340' side='right' caption='[[5kva]], [[Resolution|resolution]] 1.83&Aring;' scene=''>
+== Structural highlights ==
+<table><tr><td colspan='2'>[[5kva]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5KVA OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5KVA FirstGlance]. <br>
+</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=SAM:S-ADENOSYLMETHIONINE'>SAM</scene></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=5kva FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5kva OCA], [http://pdbe.org/5kva PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5kva RCSB], [http://www.ebi.ac.uk/pdbsum/5kva PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5kva ProSAT]</span></td></tr>
+</table>
+<div style="background-color:#fffaf0;">
+== Publication Abstract from PubMed ==
+Caffeoyl-CoA 3-O-methyltransferase (CCoAOMT) is an S-adenosyl methionine (SAM)-dependent O-methyltransferase responsible for methylation of the meta-hydroxyl group of caffeoyl-CoA, on the pathway to monolignols with their ring methoxylation status characteristic of guaiacyl or syringyl units in lignin. In order to better understand the unique class of type-2 O-methyltransferases from monocots, we have characterized CCoAOMT from sorghum (Sorghum bicolor) (SbCCoAOMT), including the SAM binary complex crystal structure, steady state enzyme kinetics, isothermal titration calorimetry (ITC), inductively coupled plasma-optical emission spectroscopy (ICP-OES) and molecular docking. Key amino acid residues were validated with site-directed mutagenesis. ITC data indicated a sequential binding mechanism for SbCCoAOMT, wherein SAM binds prior to caffeoyl-CoA, and the enzyme showed allosteric behavior with respect to it. 5-Hydroxyferuloyl-CoA was not a substrate for SbCCoAOMT. We propose a catalytic mechanism in which Lys180 acts as a catalytic base and deprotonates the reactive hydroxyl group of caffeoyl-CoA. This deprotonation is facilitated by the coordination of the reactive hydroxyl group by Ca2+ in the active site, lowering the pKa of the 3'-OH group. Collectively, these data give a new perspective on the catalytic mechanism of CCoAOMTs and provide a basis for the functional diversity exhibited by type-2 plant OMTs that contain a unique insertion loop (residues 208-231) conferring affinity for phenylpropanoid-CoA thioesters.
-Authors:
+Determination of the structure and catalytic mechanism of Sorghum bicolor caffeoyl-CoA O-methyltransferase.,Walker AM, Sattler SA, Regner MR, Jones JP, Ralph J, Vermerris W, Sattler SE, Kang C Plant Physiol. 2016 Jul 25. pii: pp.00845.2016. PMID:27457122<ref>PMID:27457122</ref>
-Description:
+From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
-[[Category: Unreleased Structures]]
+</div>
+<div class="pdbe-citations 5kva" style="background-color:#fffaf0;"></div>
+== References ==
+<references/>
+__TOC__
+</StructureSection>
+[[Category: Jones, J P]]
+[[Category: Kang, C]]
+[[Category: Ralph, J]]
+[[Category: Regner, M]]
+[[Category: Sattler, S A]]
+[[Category: Sattler, S E]]
+[[Category: Vermerris, W]]
+[[Category: Walker, A M]]
+[[Category: Caffeoyl-coa o-methyltransferase]]
+[[Category: Ccoaomt]]
+[[Category: Ccomt omt]]
+[[Category: Coenzyme some]]
+[[Category: Methyltransferase]]
+[[Category: Sam o-methyltransferase]]
+[[Category: Sbccoaomt]]
+[[Category: Transferase]]