| Structural highlights
9c4p is a 1 chain structure with sequence from Arabidopsis thaliana. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Method: | X-ray diffraction, Resolution 2.4Å |
| Ligands: | A1AUE, AUJ, CSD, FAD, MG, NHE, SO4, SRT |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
ILVB_ARATH Catalyzes the formation of acetolactate from pyruvate, the first step in valine and isoleucine biosynthesis.[1] [2] [:][3] [4] [5] [6] [7] [8]
Publication Abstract from PubMed
Triasulfuron is a commercial herbicide of the sulfonylurea family. This compound targets acetohydroxyacid synthase (AHAS, E.C. 2.2.1.6), the first enzyme in the branched chain amino acid biosynthesis pathway. Here, we have determined crystal structures of Arabidopsis thaliana AHAS (AtAHAS) in complex with triasulfuron and two newly designed herbicidal compounds, identified as FMO and CMO, showing that their binding modes are subtly different. Kinetic studies showed all three compounds exhibit varying K(i) values, 0.192 +/- 0.013 muM for triasulfuron, 0.086 +/- 0.013 muM for FMO, and 1.448 +/- 0.058 muM for CMO, but all are strong time-dependent accumulative inhibitors of AtAHAS. Apart from triasulfuron being a powerful herbicide with application rates of 10-15 g/ha in wheat fields, CMO and FMO are also herbicidal at 7.5-30 g/ha for barnyard grass. This study emphasizes that accumulative inhibition is an important factor that contributes to herbicidal activity.
Crystal Structures of Arabidopsis thaliana Acetohydroxyacid Synthase in Complex with the Herbicide Triasulfuron and Two Analogues with Herbicidal Activity in Field Trials.,Cheng Y, Wang Y, Lonhienne T, Wang JG, Guddat LW J Agric Food Chem. 2024 Oct 7. doi: 10.1021/acs.jafc.4c04990. PMID:39373624[9]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Mazur BJ, Chui CF, Smith JK. Isolation and characterization of plant genes coding for acetolactate synthase, the target enzyme for two classes of herbicides. Plant Physiol. 1987 Dec;85(4):1110-7. PMID:16665813
- ↑ Sathasivan K, Haughn GW, Murai N. Nucleotide sequence of a mutant acetolactate synthase gene from an imidazolinone-resistant Arabidopsis thaliana var. Columbia. Nucleic Acids Res. 1990 Apr 25;18(8):2188. PMID:2336405
- ↑ Haughn GW, Somerville CR. A Mutation Causing Imidazolinone Resistance Maps to the Csr1 Locus of Arabidopsis thaliana. Plant Physiol. 1990 Apr;92(4):1081-5. PMID:16667374
- ↑ Sathasivan K, Haughn GW, Murai N. Molecular Basis of Imidazolinone Herbicide Resistance in Arabidopsis thaliana var Columbia. Plant Physiol. 1991 Nov;97(3):1044-50. PMID:16668488
- ↑ Ott KH, Kwagh JG, Stockton GW, Sidorov V, Kakefuda G. Rational molecular design and genetic engineering of herbicide resistant crops by structure modeling and site-directed mutagenesis of acetohydroxyacid synthase. J Mol Biol. 1996 Oct 25;263(2):359-68. PMID:8913312 doi:https://dx.doi.org/10.1006/jmbi.1996.0580
- ↑ Chang AK, Duggleby RG. Expression, purification and characterization of Arabidopsis thaliana acetohydroxyacid synthase. Biochem J. 1997 Oct 1;327 ( Pt 1):161-9. PMID:9355748
- ↑ Chang AK, Duggleby RG. Herbicide-resistant forms of Arabidopsis thaliana acetohydroxyacid synthase: characterization of the catalytic properties and sensitivity to inhibitors of four defined mutants. Biochem J. 1998 Aug 1;333 ( Pt 3):765-77. PMID:9677339
- ↑ Lee YT, Chang AK, Duggleby RG. Effect of mutagenesis at serine 653 of Arabidopsis thaliana acetohydroxyacid synthase on the sensitivity to imidazolinone and sulfonylurea herbicides. FEBS Lett. 1999 Jun 11;452(3):341-5. PMID:10386618
- ↑ Cheng Y, Wang Y, Lonhienne T, Wang JG, Guddat LW. Crystal Structures of Arabidopsis thaliana Acetohydroxyacid Synthase in Complex with the Herbicide Triasulfuron and Two Analogues with Herbicidal Activity in Field Trials. J Agric Food Chem. 2024 Oct 7. PMID:39373624 doi:10.1021/acs.jafc.4c04990
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