View source for 8czc


==AT from first module of the pikromycin synthase==
<StructureSection load='8czc' size='340' side='right'caption='[[8czc]], [[Resolution|resolution]] 2.86&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8czc]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptomyces_venezuelae Streptomyces venezuelae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8CZC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8CZC FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 2.86&#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=8czc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8czc OCA], [https://pdbe.org/8czc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8czc RCSB], [https://www.ebi.ac.uk/pdbsum/8czc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8czc ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The first domain of modular polyketide synthases (PKSs) is most commonly a ketosynthase (KS)-like enzyme, KS(Q), that primes polyketide synthesis. Unlike downstream KSs that fuse alpha-carboxyacyl groups to growing polyketide chains, it performs an extension-decoupled decarboxylation of these groups to generate primer units. When Pik127, a model triketide synthase constructed from modules of the pikromycin synthase, was studied by cryoelectron microscopy (cryo-EM), the dimeric didomain comprised of KS(Q) and the neighboring methylmalonyl-selective acyltransferase (AT) dominated the class averages and yielded structures at 2.5- and 2.8-A resolution, respectively. Comparisons with ketosynthases complexed with their substrates revealed the conformation of the (2S)-methylmalonyl-S-phosphopantetheinyl portion of KS(Q) and KS substrates prior to decarboxylation. Point mutants of Pik127 probed the roles of residues in the KS(Q) active site, while an AT-swapped version of Pik127 demonstrated that KS(Q) can also decarboxylate malonyl groups. Mechanisms for how KS(Q) and KS domains catalyze carbon-carbon chemistry are proposed.

Priming enzymes from the pikromycin synthase reveal how assembly-line ketosynthases catalyze carbon-carbon chemistry.,Dickinson MS, Miyazawa T, McCool RS, Keatinge-Clay AT Structure. 2022 Sep 1;30(9):1331-1339.e3. doi: 10.1016/j.str.2022.05.021. Epub , 2022 Jun 22. PMID:35738283<ref>PMID:35738283</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8czc" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Streptomyces venezuelae]]
[[Category: Dickinson MS]]
[[Category: Keatinge-Clay AT]]
[[Category: McCool RS]]
[[Category: Miyazawa T]]