1T9C

Crystal Structure Of Yeast Acetohydroxyacid Synthase In Complex With A Sulfonylurea Herbicide, Sulfometuron methyl


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.34 Å
  • R-Value Free: 0.191 
  • R-Value Work: 0.162 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Elucidating the specificity of binding of sulfonylurea herbicides to acetohydroxyacid synthase.

McCourt, J.A.Pang, S.S.Guddat, L.W.Duggleby, R.G.

(2005) Biochemistry 44: 2330-2338

  • DOI: 10.1021/bi047980a
  • Primary Citation of Related Structures:  1T9A, 1T9B, 1T9D

  • PubMed Abstract: 
  • Acetohydroxyacid synthase (AHAS, EC 2.2.1.6) is the target for the sulfonylurea herbicides, which act as potent inhibitors of the enzyme. Chlorsulfuron (marketed as Glean) and sulfometuron methyl (marketed as Oust) are two commercially important memb ...

    Acetohydroxyacid synthase (AHAS, EC 2.2.1.6) is the target for the sulfonylurea herbicides, which act as potent inhibitors of the enzyme. Chlorsulfuron (marketed as Glean) and sulfometuron methyl (marketed as Oust) are two commercially important members of this family of herbicides. Here we report crystal structures of yeast AHAS in complex with chlorsulfuron (at a resolution of 2.19 A), sulfometuron methyl (2.34 A), and two other sulfonylureas, metsulfuron methyl (2.29 A) and tribenuron methyl (2.58 A). The structures observed suggest why these inhibitors have different potencies and provide clues about the differential effects of mutations in the active site tunnel on various inhibitors. In all of the structures, the thiamin diphosphate cofactor is fragmented, possibly as the result of inhibitor binding. In addition to thiamin diphosphate, AHAS requires FAD for activity. Recently, it has been reported that reduction of FAD can occur as a minor side reaction due to reaction with the carbanion/enamine of the hydroxyethyl-ThDP intermediate that is formed midway through the catalytic cycle. Here we report that the isoalloxazine ring has a bent conformation that would account for its ability to accept electrons from the hydroxyethyl intermediate. Most sequence and mutation data suggest that yeast AHAS is a high-quality model for the plant enzyme.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, The University of Queensland, Brisbane, Queensland 4072, Australia.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Acetolactate synthase, mitochondrial
A, B
677Saccharomyces cerevisiae (strain ATCC 204508 / S288c)Gene Names: ILV2 (SMR1)
EC: 2.2.1.6
Find proteins for P07342 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Go to UniProtKB:  P07342
Small Molecules
Ligands 6 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

Download SDF File 
Download CCD File 
A, B
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
P23
Query on P23

Download SDF File 
Download CCD File 
B
PROPYL TRIHYDROGEN DIPHOSPHATE
C3 H10 O7 P2
JCWMAIAFQQTSAX-UHFFFAOYSA-N
 Ligand Interaction
FAD
Query on FAD

Download SDF File 
Download CCD File 
A, B
FLAVIN-ADENINE DINUCLEOTIDE
C27 H33 N9 O15 P2
VWWQXMAJTJZDQX-UYBVJOGSSA-N
 Ligand Interaction
1SM
Query on 1SM

Download SDF File 
Download CCD File 
A, B
METHYL 2-[({[(4,6-DIMETHYLPYRIMIDIN-2-YL)AMINO]CARBONYL}AMINO)SULFONYL]BENZOATE
SULFOMETURON METHYL
C15 H16 N4 O5 S
ZDXMLEQEMNLCQG-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A, B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
P22
Query on P22

Download SDF File 
Download CCD File 
A
ETHYL DIHYDROGEN DIPHOSPHATE
C2 H8 O7 P2
OJDJHGIXNZPZFD-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
1SMKi: 51 nM (100) BINDINGDB
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.34 Å
  • R-Value Free: 0.191 
  • R-Value Work: 0.162 
  • Space Group: P 4 2 2
Unit Cell:
Length (Å)Angle (°)
a = 154.486α = 90.00
b = 154.486β = 90.00
c = 178.796γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
SCALEPACKdata scaling
Adxvdata processing
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-12-21
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-11
    Type: Refinement description