View source for 8t9q


==Crystal structure of fused YR, an asymmetric 4-OT trimer==
<StructureSection load='8t9q' size='340' side='right'caption='[[8t9q]], [[Resolution|resolution]] 2.29&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8t9q]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Herbaspirillum Herbaspirillum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8T9Q OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8T9Q 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]] 2.29&#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=8t9q FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8t9q OCA], [https://pdbe.org/8t9q PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8t9q RCSB], [https://www.ebi.ac.uk/pdbsum/8t9q PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8t9q ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/J3HY51_9BURK J3HY51_9BURK] [https://www.uniprot.org/uniprot/J2VT77_9BURK J2VT77_9BURK] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Members of the 4-oxalocrotonate tautomerase (4-OT) subgroup in the tautomerase superfamily (TSF) are constructed from a single beta-alpha-beta unit and form homo- or heterohexamers, whereas those of the other four subgroups are composed of two consecutively joined beta-alpha-beta units and form trimers. A subset of sequences, double the length of the short 4-OTs, is found in the 4-OT subgroup. These "fused" 4-OTs form a separate subgroup that connects to the short 4-OTs in a sequence similarity network (SSN). The fused gene can be a template for the other four subgroups, resulting in the diversification of activity. Analysis of the SSN shows that multiple nodes in the fused 4-OTs connect to five linker nodes, which in turn connect to the short 4-OTs. Some fused 4-OTs are symmetric trimers and others are asymmetric trimers. The origin of this asymmetry was investigated by subjecting the sequences in three linker nodes and a closely associated fourth node to kinetic, mutagenic, and structural analyses. The results show that each sequence corresponds to the alpha- or beta-subunit of a heterohexamer that functions as a 4-OT. Mutagenesis indicates that the key residues in both are alphaPro1 and betaArg-11, like that of a typical 4-OT. Crystallographic analysis shows that both heterohexamers are asymmetric, where one heterodimer is flipped 180 degrees relative to the other two heterodimers. The fusion of two subunits (alpha and beta) of one asymmetric heterohexamer generates an asymmetric trimer with 4-OT activity. Hence, asymmetry can be introduced at the heterohexamer level and then retained in the fused trimers.

Introduction of Asymmetry in the Fused 4-Oxalocrotonate Tautomerases.,Erwin K, Moreno RY, Baas BJ, Zhang YJ, Whitman CP Biochemistry. 2023 Aug 15;62(16):2461-2471. doi: 10.1021/acs.biochem.3c00180. , Epub 2023 Jul 25. PMID:37490761<ref>PMID:37490761</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8t9q" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Herbaspirillum]]
[[Category: Large Structures]]
[[Category: Moreno RY]]
[[Category: Zhang YJ]]