View source for 7bzb


==Crystal structure of plant sesterterpene synthase AtTPS18==
<StructureSection load='7bzb' size='340' side='right'caption='[[7bzb]], [[Resolution|resolution]] 2.15&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7bzb]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7BZB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7BZB 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]] 2.148&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PPV:PYROPHOSPHATE'>PPV</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=7bzb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7bzb OCA], [https://pdbe.org/7bzb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7bzb RCSB], [https://www.ebi.ac.uk/pdbsum/7bzb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7bzb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TPS18_ARATH TPS18_ARATH] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Class I terpene synthase (TPS) generates bioactive terpenoids with diverse backbones. Sesterterpene synthase (sester-TPS, C25), a branch of class I TPSs, was recently identified in Brassicaceae. However, the catalytic mechanisms of sester-TPSs are not fully understood. Here, we first identified three nonclustered functional sester-TPSs (AtTPS06, AtTPS22, and AtTPS29) in Arabidopsis thaliana. AtTPS06 utilizes a type-B cyclization mechanism, whereas most other sester-TPSs produce various sesterterpene backbones via a type-A cyclization mechanism. We then determined the crystal structure of the AtTPS18-FSPP complex to explore the cyclization mechanism of plant sester-TPSs. We used structural comparisons and site-directed mutagenesis to further elucidate the mechanism: (1) mainly due to the outward shift of helix G, plant sester-TPSs have a larger catalytic pocket than do mono-, sesqui-, and di-TPSs to accommodate GFPP; (2) type-A sester-TPSs have more aromatic residues (five or six) in their catalytic pocket than classic TPSs (two or three), which also determines whether the type-A or type-B cyclization mechanism is active; and (3) the other residues responsible for product fidelity are determined by interconversion of AtTPS18 and its close homologs. Altogether, this study improves our understanding of the catalytic mechanism of plant sester-TPS, which ultimately enables the rational engineering of sesterterpenoids for future applications.

Molecular Basis for Sesterterpene Diversity Produced by Plant Terpene Synthases.,Chen Q, Li J, Liu Z, Mitsuhashi T, Zhang Y, Liu H, Ma Y, He J, Shinada T, Sato T, Wang Y, Liu H, Abe I, Zhang P, Wang G Plant Commun. 2020 Apr 29;1(5):100051. doi: 10.1016/j.xplc.2020.100051., eCollection 2020 Sep 14. PMID:33367256<ref>PMID:33367256</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7bzb" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Arabidopsis thaliana]]
[[Category: Large Structures]]
[[Category: Li JX]]
[[Category: Wang GD]]
[[Category: Zhang P]]