View source for 9tb4


==SAM-dependent C6-FPP methytransferase from Streptomyces varsoviensis in complex with SAH and FPP==
<StructureSection load='9tb4' size='340' side='right'caption='[[9tb4]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9tb4]] is a 12 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptomyces Streptomyces]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9TB4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9TB4 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]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=FPP:FARNESYL+DIPHOSPHATE'>FPP</scene>, <scene name='pdbligand=PE8:3,6,9,12,15,18,21-HEPTAOXATRICOSANE-1,23-DIOL'>PE8</scene>, <scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</scene>, <scene name='pdbligand=PG4:TETRAETHYLENE+GLYCOL'>PG4</scene>, <scene name='pdbligand=PGE:TRIETHYLENE+GLYCOL'>PGE</scene>, <scene name='pdbligand=SAH:S-ADENOSYL-L-HOMOCYSTEINE'>SAH</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=9tb4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9tb4 OCA], [https://pdbe.org/9tb4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9tb4 RCSB], [https://www.ebi.ac.uk/pdbsum/9tb4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9tb4 ProSAT]</span></td></tr>
</table>
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== Publication Abstract from PubMed ==
Non-canonical methylation events generate terpene structures that evade classical biosynthetic predictions, as exemplified by the proposed C(16) terpene hegelenether. Here, we show that this natural product is misassigned and revise its structure to the dihydroxylated sesquiterpenoid marxdiol. Its absolute configuration and that of its precursor prekantenol pyrophosphate were determined through terpene synthase-mediated incorporation of stereoselectively labeled probes. To explain the initiating C6 methylation, we solved the crystal structure of the methyltransferase C6-FPP-MT with SAH and FPP, revealing a compact aromatic pocket that enforces Si-face methylation and Glu165-mediated deprotonation. These insights define how the active site controls regio- and stereochemistry and provide a structural basis for identifying related methyl-modified terpenes in uncharacterized biosynthetic pathways.

Structural Revision of the C(16) Sesquiterpene Hegelenether and the Mechanism of C6-Methylation in Terpene Biosynthesis.,Li H, Schnakenburg G, Groll M, Dickschat JS Angew Chem Int Ed Engl. 2026 Jan 15:e25672. doi: 10.1002/anie.202525672. PMID:41540682<ref>PMID:41540682</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9tb4" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Streptomyces]]
[[Category: Dickschat JS]]
[[Category: Groll M]]
[[Category: Li H]]
[[Category: Schnakenburg G]]