5K6Q

Crystal structure of Arabidopsis thaliana acetohydroxyacid synthase catalytic subunit


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.95 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.193 

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.1 of the entry. See complete history


Literature

Crystal structure of plant acetohydroxyacid synthase, the target for several commercial herbicides.

Garcia, M.D.Wang, J.G.Lonhienne, T.Guddat, L.W.

(2017) FEBS J 284: 2037-2051

  • DOI: 10.1111/febs.14102
  • Primary Citation of Related Structures:  
    5K6Q

  • PubMed Abstract: 
  • Acetohydroxyacid synthase (AHAS, EC 2.2.1.6) is the first enzyme in the branched-chain amino acid biosynthesis pathway. Five of the most widely used commercial herbicides (i.e. sulfonylureas, imidazolinones, triazolopyrimidines, pyrimidinyl-benzoates and sulfonylamino-cabonyl-triazolinones) target this enzyme ...

    Acetohydroxyacid synthase (AHAS, EC 2.2.1.6) is the first enzyme in the branched-chain amino acid biosynthesis pathway. Five of the most widely used commercial herbicides (i.e. sulfonylureas, imidazolinones, triazolopyrimidines, pyrimidinyl-benzoates and sulfonylamino-cabonyl-triazolinones) target this enzyme. Here we have determined the first crystal structure of a plant AHAS in the absence of any inhibitor (2.9 Å resolution) and it shows that the herbicide-binding site adopts a folded state even in the absence of an inhibitor. This is unexpected because the equivalent regions for herbicide binding in uninhibited Saccharomyces cerevisiae AHAS crystal structures are either disordered, or adopt a different fold when the herbicide is not present. In addition, the structure provides an explanation as to why some herbicides are more potent inhibitors of Arabidopsis thaliana AHAS compared to AHASs from other species (e.g. S. cerevisiae). The elucidation of the native structure of plant AHAS provides a new platform for future rational structure-based herbicide design efforts.


    Organizational Affiliation

    School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Acetolactate synthase, chloroplasticA590Arabidopsis thalianaMutation(s): 0 
Gene Names: ALSAHASCSR1TZP5At3g48560T8P19.70ILVB
EC: 2.2.1.6
UniProt
Find proteins for P17597 (Arabidopsis thaliana)
Explore P17597 
Go to UniProtKB:  P17597
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FAD (Subject of Investigation/LOI)
Query on FAD

Download Ideal Coordinates CCD File 
C [auth A]FLAVIN-ADENINE DINUCLEOTIDE
C27 H33 N9 O15 P2
VWWQXMAJTJZDQX-UYBVJOGSSA-N
 Ligand Interaction
TDM (Subject of Investigation/LOI)
Query on TDM

Download Ideal Coordinates CCD File 
E [auth A]2-[(2E)-3-[(4-AMINO-2-METHYLPYRIMIDIN-5-YL)METHYL]-2-(1-HYDROXYETHYLIDENE)-4-METHYL-2,3-DIHYDRO-1,3-THIAZOL-5-YL]ETHYL TRIHYDROGEN DIPHOSPHATE
C14 H22 N4 O8 P2 S
ZZLCKFKIIVXBQU-NTEUORMPSA-N
 Ligand Interaction
NHE
Query on NHE

Download Ideal Coordinates CCD File 
D [auth A]2-[N-CYCLOHEXYLAMINO]ETHANE SULFONIC ACID
C8 H17 N O3 S
MKWKNSIESPFAQN-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

Download Ideal Coordinates CCD File 
B [auth A]MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
CSD
Query on CSD
AL-PEPTIDE LINKINGC3 H7 N O4 SCYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.95 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.193 
  • Space Group: P 64 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 178.934α = 90
b = 178.934β = 90
c = 186.086γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment  



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2017-05-31
    Type: Initial release
  • Version 1.1: 2017-07-12
    Changes: Database references