6DEP

Crystal structure of Candida albicans acetohydroxyacid synthase in complex with the herbicide sulfometuron methyl


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.172 
  • R-Value Work: 0.144 
  • R-Value Observed: 0.145 

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

Commercial AHAS-inhibiting herbicides are promising drug leads for the treatment of human fungal pathogenic infections.

Garcia, M.D.Chua, S.M.H.Low, Y.S.Lee, Y.T.Agnew-Francis, K.Wang, J.G.Nouwens, A.Lonhienne, T.Williams, C.M.Fraser, J.A.Guddat, L.W.

(2018) Proc Natl Acad Sci U S A 115: E9649-E9658

  • DOI: 10.1073/pnas.1809422115
  • Primary Citation of Related Structures:  
    6DEK, 6DEL, 6DEM, 6DEN, 6DEO, 6DEP, 6DEQ, 6DER, 6DES

  • PubMed Abstract: 
  • The increased prevalence of drug-resistant human pathogenic fungal diseases poses a major threat to global human health. Thus, new drugs are urgently required to combat these infections. Here, we demonstrate that acetohydroxyacid synthase (AHAS), the first enzyme in the branched-chain amino acid biosynthesis pathway, is a promising new target for antifungal drug discovery ...

    The increased prevalence of drug-resistant human pathogenic fungal diseases poses a major threat to global human health. Thus, new drugs are urgently required to combat these infections. Here, we demonstrate that acetohydroxyacid synthase (AHAS), the first enzyme in the branched-chain amino acid biosynthesis pathway, is a promising new target for antifungal drug discovery. First, we show that several AHAS inhibitors developed as commercial herbicides are powerful accumulative inhibitors of Candida albicans AHAS ( K i values as low as 800 pM) and have determined high-resolution crystal structures of this enzyme in complex with several of these herbicides. In addition, we have demonstrated that chlorimuron ethyl (CE), a member of the sulfonylurea herbicide family, has potent antifungal activity against five different Candida species and Cryptococcus neoformans (with minimum inhibitory concentration, 50% values as low as 7 nM). Furthermore, in these assays, we have shown CE and itraconazole (a P450 inhibitor) can act synergistically to further improve potency. Finally, we show in Candida albicans -infected mice that CE is highly effective in clearing pathogenic fungal burden in the lungs, liver, and spleen, thus reducing overall mortality rates. Therefore, in view of their low toxicity to human cells, AHAS inhibitors represent a new class of antifungal drug candidates.


    Organizational Affiliation

    School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia; luke.guddat@uq.edu.au.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Acetolactate synthaseA682Candida albicans SC5314Mutation(s): 0 
Gene Names: ILV2orf19.1613CAALFM_C302320WA
EC: 2.2.1.6
UniProt
Find proteins for A0A1D8PJF9 (Candida albicans (strain SC5314 / ATCC MYA-2876))
Explore A0A1D8PJF9 
Go to UniProtKB:  A0A1D8PJF9
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A1D8PJF9
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 6 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FAD
Query on FAD

Download Ideal Coordinates CCD File 
B [auth A]FLAVIN-ADENINE DINUCLEOTIDE
C27 H33 N9 O15 P2
VWWQXMAJTJZDQX-UYBVJOGSSA-N
 Ligand Interaction
TZD
Query on TZD

Download Ideal Coordinates CCD File 
F [auth A]2-{3-[(4-AMINO-2-METHYLPYRIMIDIN-5-YL)METHYL]-4-METHYL-2-OXO-2,3-DIHYDRO-1,3-THIAZOL-5-YL}ETHYL TRIHYDROGEN DIPHOSPHATE
C12 H18 N4 O8 P2 S
ZGJUYGIRPQSCFA-UHFFFAOYSA-N
 Ligand Interaction
TP9
Query on TP9

Download Ideal Coordinates CCD File 
G [auth A](3Z)-4-{[(4-AMINO-2-METHYLPYRIMIDIN-5-YL)METHYL]AMINO}-3-MERCAPTOPENT-3-EN-1-YL TRIHYDROGEN DIPHOSPHATE
C11 H18 N4 O7 P2 S
WTQDUFKDQLXDPH-YFHOEESVSA-L
 Ligand Interaction
1SM
Query on 1SM

Download Ideal Coordinates CCD File 
E [auth A]METHYL 2-[({[(4,6-DIMETHYLPYRIMIDIN-2-YL)AMINO]CARBONYL}AMINO)SULFONYL]BENZOATE
C15 H16 N4 O5 S
ZDXMLEQEMNLCQG-UHFFFAOYSA-N
 Ligand Interaction
K
Query on K

Download Ideal Coordinates CCD File 
C [auth A]POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

Download Ideal Coordinates CCD File 
D [auth A]MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.172 
  • R-Value Work: 0.144 
  • R-Value Observed: 0.145 
  • Space Group: P 62 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 175.893α = 90
b = 175.893β = 90
c = 177.029γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XDSdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Health and Medical Research Council (NHMRC, Australia)Australia1008736

Revision History  (Full details and data files)

  • Version 1.0: 2018-09-26
    Type: Initial release
  • Version 1.1: 2018-10-10
    Changes: Data collection, Database references, Structure summary
  • Version 1.2: 2018-10-17
    Changes: Data collection, Database references, Structure summary
  • Version 1.3: 2020-01-08
    Changes: Author supporting evidence