View source for 9uuv


==beta barrel protein-LucK==
<StructureSection load='9uuv' size='340' side='right'caption='[[9uuv]], [[Resolution|resolution]] 1.87&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9uuv]] is a 2 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=9UUV OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9UUV 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]] 1.87&#8491;</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=9uuv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9uuv OCA], [https://pdbe.org/9uuv PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9uuv RCSB], [https://www.ebi.ac.uk/pdbsum/9uuv PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9uuv ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Lucensimycin A is a structurally unique spirotetronate polyketide featuring a rare spiro[tetronate-hydrophenanthrene] tetracyclic core, distinct from the classical spiro[tetronate-cyclohexene] scaffolds formed via intramolecular Diels-Alder (IMDA) cyclizations. Here, we identified and characterized the luc biosynthetic gene cluster from Streptomyces fagopyri NAX0062, revealing a divergent biosynthetic logic. The pathway begins with type I PKS assembly of a linear polyketide, followed by tetronate ring formation by a canonical tetronate cassette. A flavin-dependent Diels-Alderase (LucM) then catalyzes an IMDA reaction to form a decalin intermediate. Unusually, the Diels-Alderase homologue LucK catalyzes a stereoselective intramolecular nucleophilic cyclization horizontal line rather than a pericyclic reaction horizontal line to generate the spiro[tetronate-hydrophenanthrene] core, following acetylation by LucN. Oxidative cleavage of a terminal alkene (by LucO3) completes the pathway. Structural and mutational analysis of LucK revealed that Glu16 and Glu85 function as general acid/base catalysts to drive the nucleophilic cyclization reaction, highlighting LucK as a mechanistically distinct cyclase. This work uncovers a previously unrecognized enzymatic strategy for spirocyclic construction and expands the catalytic repertoire of beta-barrel enzymes in polyketide biosynthesis.

Enzymatic Stereoselective Nucleophilic Cyclization Governs Atypical Spirotetronate Assembly in Lucensimycin A Biosynthesis.,Xi MY, Zhang B, Peng T, Ma XX, Zhu A, Wang ZJ, Gu Y, Tan RX, Ge HM J Am Chem Soc. 2025 Jul 9;147(27):24077-24084. doi: 10.1021/jacs.5c07754. Epub , 2025 Jun 26. PMID:40569275<ref>PMID:40569275</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9uuv" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Streptomyces]]
[[Category: Ge HM]]
[[Category: Ma XX]]
[[Category: Zhang B]]