2efj: Difference between revisions

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-[[Image:2efj.jpg|left|200px]]<br /><applet load="2efj" size="350" color="white" frame="true" align="right" spinBox="true"
-caption="2efj, resolution 2.00&Aring;" />
-'''The structure of 1,7 dimethylxanthine methyltransferase'''<br />
-==Overview==
+==The structure of 1,7 dimethylxanthine methyltransferase==
-Caffeine (1,3,7-trimethylxanthine) is a secondary metabolite produced by certain plant species and an important component of coffee (Coffea arabica and Coffea canephora) and tea (Camellia sinensis). Here we describe the structures of two S-adenosyl-l-methionine-dependent N-methyltransferases that mediate caffeine biosynthesis in C. canephora 'robusta', xanthosine (XR) methyltransferase (XMT), and 1,7-dimethylxanthine methyltransferase (DXMT). Both were cocrystallized with the demethylated cofactor, S-adenosyl-L-cysteine, and substrate, either xanthosine or theobromine. Our structures reveal several elements that appear critical for substrate selectivity. Serine-316 in XMT appears central to the recognition of XR. Likewise, a change from glutamine-161 in XMT to histidine-160 in DXMT is likely to have catalytic consequences. A phenylalanine-266 to isoleucine-266 change in DXMT is also likely to be crucial for the discrimination between mono and dimethyl transferases in coffee. These key residues are probably functionally important and will guide future studies with implications for the biosynthesis of caffeine and its derivatives in plants.
+<StructureSection load='2efj' size='340' side='right'caption='[[2efj]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
+== Structural highlights ==
-==About this Structure==
+<table><tr><td colspan='2'>[[2efj]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Coffea_canephora Coffea canephora]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2EFJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2EFJ FirstGlance]. <br>
-EFJ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Coffea_canephora Coffea canephora] with <scene name='pdbligand=SAH:'>SAH</scene> and <scene name='pdbligand=37T:'>37T</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2EFJ OCA].
+</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2&#8491;</td></tr>
+<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=37T:THEOBROMINE'>37T</scene>, <scene name='pdbligand=SAH:S-ADENOSYL-L-HOMOCYSTEINE'>SAH</scene></td></tr>
-==Reference==
+<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2efj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2efj OCA], [https://pdbe.org/2efj PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2efj RCSB], [https://www.ebi.ac.uk/pdbsum/2efj PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2efj ProSAT]</span></td></tr>
-The structure of two N-methyltransferases from the caffeine biosynthetic pathway., McCarthy AA, McCarthy JG, Plant Physiol. 2007 Jun;144(2):879-89. Epub 2007 Apr 13. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17434991 17434991]
+</table>
+== Function ==
+[https://www.uniprot.org/uniprot/DXMT1_COFCA DXMT1_COFCA] Involved in the biosynthesis of caffeine. Catalyzes the conversion of 7-methylxanthine to theobromine and of theobromine to caffeine, but no sequential conversion of 7-methylxanthine to caffeine was detected.
+== 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/ef/2efj_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=2efj ConSurf].
+<div style="clear:both"></div>
+__TOC__
+</StructureSection>
 [[Category: Coffea canephora]]
-[[Category: Single protein]]
+[[Category: Large Structures]]
-[[Category: McCarthy, A A.]]
+[[Category: McCarthy AA]]
-[[Category: McCarthy, J G.]]
+[[Category: McCarthy JG]]
-[[Category: 37T]]
-[[Category: SAH]]
-[[Category: sah]]
-[[Category: sam-dependant methyltransferase]]
-[[Category: theobromine]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:09:33 2008''