View source for 8et4


==Crystal structure of wild-type arabidopsis thaliana acetohydroxyacid synthase in complex with amidosulfuron==
<StructureSection load='8et4' size='340' side='right'caption='[[8et4]], [[Resolution|resolution]] 2.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8et4]] 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=8ET4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8ET4 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]] 2.95&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=AUJ:2-[3-[(4-azanyl-2-methyl-pyrimidin-5-yl)methyl]-2-[(1S)-1-(dioxidanyl)-1-oxidanyl-ethyl]-4-methyl-1,3-thiazol-5-yl]ethyl+phosphono+hydrogen+phosphate'>AUJ</scene>, <scene name='pdbligand=CSD:3-SULFINOALANINE'>CSD</scene>, <scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NHE:2-[N-CYCLOHEXYLAMINO]ETHANE+SULFONIC+ACID'>NHE</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=TLA:L(+)-TARTARIC+ACID'>TLA</scene>, <scene name='pdbligand=WRQ:N-{[(4,6-dimethoxypyrimidin-2-yl)carbamoyl]sulfamoyl}-N-methylmethanesulfonamide'>WRQ</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=8et4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8et4 OCA], [https://pdbe.org/8et4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8et4 RCSB], [https://www.ebi.ac.uk/pdbsum/8et4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8et4 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ILVB_ARATH ILVB_ARATH] Catalyzes the formation of acetolactate from pyruvate, the first step in valine and isoleucine biosynthesis.<ref>PMID:16665813</ref> <ref>PMID:2336405</ref> [:]<ref>PMID:16667374</ref> <ref>PMID:16668488</ref> <ref>PMID:8913312</ref> <ref>PMID:9355748</ref> <ref>PMID:9677339</ref> <ref>PMID:10386618</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Amidosulfuron (AS) is from the commercial sulfonylurea herbicide family. It is highly effective against dicot broad-leaf weeds. This herbicide targets acetohydroxyacid synthase (AHAS), the first enzyme in the branched chain amino acid biosynthesis pathway. Here, we have determined the crystal structure of AS in complex with wildtype Arabidopsis thaliana AHAS (AtAHAS) and with the resistance mutant, S653T. In both structures, the cofactor, ThDP, is modified to a peracetate adduct, consistent with time-dependent accumulative inhibition. Compared to other AHAS-inhibiting herbicides of the sulfonylurea family, AS lacks a second aromatic ring. The replacement is an aryl sulfonyl group with a reduced number of interactions with the enzyme and relatively low affinity (K(i) = 4.2 muM vs low nM when two heteroaromatic rings are present). This study shows that effective herbicides can have a relatively high K(i) for plant AHAS but can still be a potent herbicide provided accumulative inhibition also occurs.

Crystal Structure of the Commercial Herbicide, Amidosulfuron, in Complex with Arabidopsis thaliana Acetohydroxyacid Synthase.,Cheng Y, Lonhienne T, Garcia MD, Williams CM, Schenk G, Guddat LW J Agric Food Chem. 2023 Apr 5;71(13):5117-5126. doi: 10.1021/acs.jafc.2c08528. , Epub 2023 Mar 21. PMID:36943718<ref>PMID:36943718</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8et4" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Arabidopsis thaliana]]
[[Category: Large Structures]]
[[Category: Cheng Y]]
[[Category: Guddat LW]]