title: Structure and mechanism of inhibition of plant acetohydroxyacid synthase.
abstract: Plants and microorganisms synthesize valine, leucine and isoleucine via a common pathway in which the first reaction is catalysed by acetohydroxyacid synthase (AHAS, EC 2.2.1.6). This enzyme is of substantial importance because it is the target of several herbicides, including all members of the popular sulfonylurea and imidazolinone families. However, the emergence of resistant weeds due to mutations that interfere with the inhibition of AHAS is now a worldwide problem. Here we summarize recent ideas on the way in which these herbicides inhibit the enzyme, based on the 3D structure of Arabidopsis thaliana AHAS. This structure also reveals important clues for understanding how various mutations can lead to herbicide resistance.
authors.affiliation: RDBiotech, 22 Parklands Boulevard, Little Mountain, Queensland 4551, Australia. ron_duggleby@fastmail.com.au
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Duggleby
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: McCourt
authors.forename: Luke W
authors.initials: LW
authors.lastname: Guddat
mesh_terms: D000095:Acetolactate Synthase / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D006540:Herbicides / Q000737:chemistry / Q000494:pharmacology*; D008958:Models, Molecular; D015394:Molecular Structure; D010940:Plant Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D013237:Stereoisomerism; D013453:Sulfonylurea Compounds / Q000737:chemistry / Q000494:pharmacology
chemical_list: D006540:Herbicides; D010940:Plant Proteins; D013453:Sulfonylurea Compounds; D000095:Acetolactate Synthase