5FEM

Saccharomyces cerevisiae Acetohydroxyacid Synthase in complex with bensulfuron methyl

Summary for 5FEM

• Entry DOI: 10.2210/pdb5fem/pdb
• Descriptor: Acetolactate synthase catalytic subunit, mitochondrial, MAGNESIUM ION, FLAVIN-ADENINE DINUCLEOTIDE, ... (6 entities in total)
• Functional Keywords: herbicide, sulfonylurea, branched-chain amino acid, acetohydroxyacid synthase, thdp, fad, pyruvate, transferase
• Biological source: Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
• Total number of polymer chains: 2
• Total formula weight: 150535.06

Authors

Guddat, L.W.,Lonhienne, T. (deposition date: 2015-12-17, release date: 2016-03-16, Last modification date: 2023-09-27)

Primary citation

Lonhienne, T.,Nouwens, A.,Williams, C.M.,Fraser, J.A.,Lee, Y.T.,West, N.P.,Guddat, L.W.
Commercial Herbicides Can Trigger the Oxidative Inactivation of Acetohydroxyacid Synthase.
Angew.Chem.Int.Ed.Engl., 55:4247-4251, 2016

PubMed Abstract: Acetohydroxyacid synthase (AHAS) inhibitors are highly successful commercial herbicides. New kinetic data show that the binding of these compounds leads to reversible accumulative inhibition of AHAS. Crystallographic data (to a resolution of 2.17 Å) for an AHAS-herbicide complex shows that closure of the active site occurs when the herbicidal inhibitor binds, thus preventing exchange with solvent. This feature combined with new kinetic data shows that molecular oxygen promotes an accumulative inhibition leading to the conclusion that the exceptional potency of these herbicides is augmented by subversion of an inherent oxygenase side reaction. The reactive oxygen species produced by this reaction are trapped in the active site, triggering oxidation reactions that ultimately lead to the alteration of the redox state of the cofactor flavin adenine dinucleotide (FAD), a feature that accounts for the observed reversible accumulative inhibition.

PubMed: 26924714
DOI: 10.1002/anie.201511985

Experimental method

X-RAY DIFFRACTION (2.168 Å)