View source for 6p3o


==Tetrahydroprotoberberine N-methyltransferase in complex with (S)-cis-N-methylstylopine and S-adenosylhomocysteine==
<StructureSection load='6p3o' size='340' side='right'caption='[[6p3o]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6p3o]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Glaucium_flavum Glaucium flavum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6P3O OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6P3O 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]] 1.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SAH:S-ADENOSYL-L-HOMOCYSTEINE'>SAH</scene>, <scene name='pdbligand=SYT:(5S,12bS)-5-methyl-6,7,12b,13-tetrahydro-2H,4H,10H-[1,3]dioxolo[4,5-g][1,3]dioxolo[7,8]isoquinolino[3,2-a]isoquinolin-5-ium'>SYT</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=6p3o FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6p3o OCA], [https://pdbe.org/6p3o PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6p3o RCSB], [https://www.ebi.ac.uk/pdbsum/6p3o PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6p3o ProSAT]</span></td></tr>
</table>
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== Publication Abstract from PubMed ==
Benzylisoquinoline alkaloids (BIAs) are a structurally diverse class of plant specialized metabolites that have been particularly well studied in the order Ranunculales. The N-methyltransferases (NMTs) in BIA biosynthesis can be divided into three groups according to substrate specificity and amino acid sequence. Here, we report the first crystal structures of enzyme complexes from the tetrahydroprotoberberine NMT (TNMT) subclass, specifically for GfTNMT from yellow horned poppy (Glaucium flavum). GfTNMT was co-crystallized with the cofactor S-adenosyl-L-methionine (dmin = 1.6 A), product S-adenosyl-L-homocysteine (dmin = 1.8 A), or in complex with S-adenosyl-L-homocysteine and (S)-cis-N-methylstylopine (dmin = 1.8 A), These structures reveal for the first time how a mostly hydrophobic L-shaped substrate recognition pocket selects for the (S)-cis configuration of the two central six-membered rings in protoberberine BIA compounds. Mutagenesis studies confirm and functionally define the roles of several highly conserved residues within and near the GfTNMT active site. The substrate specificity of TNMT enzymes appears to arise from the arrangement of subgroup-specific stereospecific recognition elements relative to catalytic elements that are more widely conserved among all BIA NMTs. The binding mode of protoberberine compounds to GfTNMT appears to be similar to coclaurine NMT, with the isoquinoline rings buried deepest in the binding pocket. This binding mode differs from that of pavine NMT, in which the benzyl ring is bound more deeply than the isoquinoline rings. The insights into substrate recognition and catalysis provided here form a sound basis for the rational engineering of NMT enzymes for chemoenzymatic synthesis and metabolic engineering.

Structure-function studies of tetrahydroprotoberberine N-methyltransferase reveal the molecular basis of stereoselective substrate recognition.,Lang DE, Morris JS, Rowley M, Torres MA, Maksimovich VA, Facchini PJ, Ng KKS J Biol Chem. 2019 Aug 7. pii: RA119.009214. doi: 10.1074/jbc.RA119.009214. PMID:31395658<ref>PMID:31395658</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 6p3o" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Glaucium flavum]]
[[Category: Large Structures]]
[[Category: Facchini PJ]]
[[Category: Lang DE]]
[[Category: Maksimovich VA]]
[[Category: Morris JS]]
[[Category: Ng KKS]]
[[Category: Rowley M]]
[[Category: Torres MA]]