Crystal structure of a thermostable aldo-keto reductase Tm1743 in complex with inhibitor tolrestat

Experimental Data Snapshot

  • Resolution: 1.60 Å
  • R-Value Free: 0.190 
  • R-Value Work: 0.171 
  • R-Value Observed: 0.172 

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Tolrestat acts atypically as a competitive inhibitor of the thermostable aldo-keto reductase Tm1743 from Thermotoga maritima.

Zhang, C.Min, Z.Liu, X.Wang, C.Wang, Z.Shen, J.Tang, W.Zhang, X.Liu, D.Xu, X.

(2020) FEBS Lett 594: 564-580

  • DOI: https://doi.org/10.1002/1873-3468.13630
  • Primary Citation of Related Structures:  
    6KIK, 6KIY, 6KY6

  • PubMed Abstract: 

    Tolrestat and epalrestat have been characterized as noncompetitive inhibitors of aldo-ketone reductase 1B1 (AKR1B1), a leading drug target for the treatment of type 2 diabetes complications. However, clinical applications are limited for most AKR1B1 inhibitors due to adverse effects of cross-inhibition with other AKRs. Here, we report an atypical competitive binding and inhibitory effect of tolrestat on the thermostable AKR Tm1743 from Thermotoga maritima. Analysis of the Tm1743 crystal structure in complex with tolrestat alone and epalrestat-NADP + shows that tolrestat, but not epalrestat, binding triggers dramatic conformational changes in the anionic site and cofactor binding pocket that prevents accommodation of NADP + . Enzymatic and molecular dynamics simulation analyses further confirm tolrestat as a competitive inhibitor of Tm1743.

  • Organizational Affiliation

    School of Medicine, Hangzhou Normal University, China.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Oxidoreductase, aldo/keto reductase family275Thermotoga maritima MSB8Mutation(s): 0 
Gene Names: TM_1743
Find proteins for Q9X265 (Thermotoga maritima (strain ATCC 43589 / DSM 3109 / JCM 10099 / NBRC 100826 / MSB8))
Explore Q9X265 
Go to UniProtKB:  Q9X265
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9X265
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
TOL (Subject of Investigation/LOI)
Query on TOL

Download Ideal Coordinates CCD File 
C16 H14 F3 N O3 S
Experimental Data & Validation

Experimental Data

  • Resolution: 1.60 Å
  • R-Value Free: 0.190 
  • R-Value Work: 0.171 
  • R-Value Observed: 0.172 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 84.594α = 90
b = 84.594β = 90
c = 92.99γ = 120
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
HKL-2000data scaling
Cootmodel building

Structure Validation

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Ligand Structure Quality Assessment 

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Natural Science Foundation of ChinaChina31570738
National Natural Science Foundation of ChinaChina31870740
National Natural Science Foundation of ChinaChina31400630

Revision History  (Full details and data files)

  • Version 1.0: 2019-09-25
    Type: Initial release
  • Version 1.1: 2020-04-08
    Changes: Database references
  • Version 1.2: 2023-11-22
    Changes: Data collection, Database references, Refinement description