1T9D

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.195 
  • R-Value Work: 0.164 

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, 1T9C

  • 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, C, D
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 7 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

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

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

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Download CCD File 
A, B, C
METHYL 2-[({[(4-METHOXY-6-METHYL-1,3,5-TRIAZIN-2-YL)AMINO]CARBONYL}AMINO)SULFONYL]BENZOATE
METSULFURON METHYL
C14 H15 N5 O6 S
RSMUVYRMZCOLBH-UHFFFAOYSA-N
 Ligand Interaction
P25
Query on P25

Download SDF File 
Download CCD File 
A, B
PENTYL TRIHYDROGEN DIPHOSPHATE
C5 H14 O7 P2
VFFCVKZHJFIUBM-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

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Download CCD File 
A, B, C, D
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
PYD
Query on PYD

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Download CCD File 
A, B, C, D
2,5-DIMETHYL-PYRIMIDIN-4-YLAMINE
C6 H9 N3
UXKNAXNFIYFMIB-UHFFFAOYSA-N
 Ligand Interaction
P22
Query on P22

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Download CCD File 
C, D
ETHYL DIHYDROGEN DIPHOSPHATE
C2 H8 O7 P2
OJDJHGIXNZPZFD-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
1MMKi: 9.4 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.195 
  • R-Value Work: 0.164 
  • Space Group: I 4 2 2
Unit Cell:
Length (Å)Angle (°)
a = 218.347α = 90.00
b = 218.347β = 90.00
c = 361.530γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
AMoREphasing
CNSrefinement
Adxvdata processing

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: Advisory, Refinement description