View source for 8cq6


==Bifunctional cyclohexadienyl dehydratase/chorismate mutase from Duganella sacchari==
<StructureSection load='8cq6' size='340' side='right'caption='[[8cq6]], [[Resolution|resolution]] 2.44&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8cq6]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Duganella_sacchari Duganella sacchari]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8CQ6 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8CQ6 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]] 2.44&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=8cq6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8cq6 OCA], [https://pdbe.org/8cq6 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8cq6 RCSB], [https://www.ebi.ac.uk/pdbsum/8cq6 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8cq6 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A0A1M7QNQ8_9BURK A0A1M7QNQ8_9BURK] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Chorismate mutase (CM) and cyclohexadienyl dehydratase (CDT) catalyze two subsequent reactions in the intracellular biosynthesis of l-phenylalanine (Phe). Here, we report the discovery of novel and extremely rare bifunctional fusion enzymes, consisting of fused CM and CDT domains, which are exported from the cytoplasm. Such enzymes were found in only nine bacterial species belonging to non-pathogenic gamma- or beta-Proteobacteria. In gamma-proteobacterial fusion enzymes, the CM domain is N-terminal to the CDT domain, whereas the order is inverted in beta-Proteobacteria. The CM domains share 15% to 20% sequence identity with the AroQ(gamma) class CM holotype of Mycobacterium tuberculosis ( *MtCM), and the CDT domains 40% to 60% identity with the exported monofunctional enzyme of Pseudomonas aeruginosa (PheC). In vitro kinetics revealed a K(m) &lt;7 muM, much lower than for *MtCM, whereas kinetic parameters are similar for CDT domains and PheC. There is no feedback inhibition of CM or CDT by the pathway's end product Phe, and no catalytic benefit of the domain fusion compared with engineered single-domain constructs. The fusion enzymes of Aequoribacter fuscus, Janthinobacterium sp. HH01, and Duganella sacchari were crystallized and their structures refined to 1.6, 1.7, and 2.4 A resolution, respectively. Neither the crystal structures nor the size-exclusion chromatography show evidence for substrate channeling or higher oligomeric structure that could account for the cooperation of CM and CDT active sites. The genetic neighborhood with genes encoding transporter and substrate binding proteins suggests that these exported bifunctional fusion enzymes may participate in signaling systems rather than in the biosynthesis of Phe.

Novel exported fusion enzymes with chorismate mutase and cyclohexadienyl dehydratase activity: Shikimate pathway enzymes teamed up in no man's land.,Stocker C, Khatanbaatar T, Bressan L, Wurth-Roderer K, Cordara G, Krengel U, Kast P J Biol Chem. 2023 Oct;299(10):105161. doi: 10.1016/j.jbc.2023.105161. Epub 2023 , Aug 14. PMID:37586588<ref>PMID:37586588</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8cq6" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Duganella sacchari]]
[[Category: Large Structures]]
[[Category: Cordara G]]
[[Category: Khatanbaatar T]]
[[Category: Krengel U]]