7U1D image
Entry Detail
PDB ID:
7U1D
Keywords:
Title:
Crystal structure of arabidopsis thaliana acetohydroxyacid synthase P197T mutant in complex with chlorimuron-ethyl
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2022-02-21
Release Date:
2022-06-01
Method Details:
Experimental Method:
Resolution:
3.11 Å
R-Value Free:
0.20
R-Value Work:
0.17
R-Value Observed:
0.17
Space Group:
P 64 2 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Acetolactate synthase, chloroplastic
Mutations:P197T
Chain IDs:A
Chain Length:582
Number of Molecules:1
Biological Source:Arabidopsis thaliana
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
CSD A CYS modified residue
Primary Citation
Structural basis of resistance to herbicides that target acetohydroxyacid synthase.
Nat Commun 13 3368 3368 (2022)
PMID: 35690625 DOI: 10.1038/s41467-022-31023-x

Abstact

Acetohydroxyacid synthase (AHAS) is the target for more than 50 commercial herbicides; first applied to crops in the 1980s. Since then, 197 site-of-action resistance isolates have been identified in weeds, with mutations at P197 and W574 the most prevalent. Consequently, AHAS is at risk of not being a useful target for crop protection. To develop new herbicides, a functional understanding to explain the effect these mutations have on activity is required. Here, we show that these mutations can have two effects (i) to reduce binding affinity of the herbicides and (ii) to abolish time-dependent accumulative inhibition, critical to the exceptional effectiveness of this class of herbicide. In the two mutants, conformational changes occur resulting in a loss of accumulative inhibition by most herbicides. However, bispyribac, a bulky herbicide is able to counteract the detrimental effects of these mutations, explaining why no site-of-action resistance has yet been reported for this herbicide.

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