High-resolution crystal structure of wild-type KSI in the apo form at neutral pH

Experimental Data Snapshot

  • Resolution: 1.50 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.150 
  • R-Value Observed: 0.152 

wwPDB Validation   3D Report Full Report

This is version 1.3 of the entry. See complete history


Incorporation of rapid thermodynamic data in fragment-based drug discovery.

Kobe, A.Caaveiro, J.M.M.Tashiro, S.Kajihara, D.Kikkawa, M.Mitani, T.Tsumoto, K.

(2013) J Med Chem 56: 2155-2159

  • DOI: https://doi.org/10.1021/jm301603n
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Fragment-based drug discovery (FBDD) has enjoyed increasing popularity in recent years. We introduce SITE (single-injection thermal extinction), a novel thermodynamic methodology that selects high-quality hits early in FBDD. SITE is a fast calorimetric competitive assay suitable for automation that captures the essence of isothermal titration calorimetry but using significantly fewer resources. We describe the principles of SITE and identify a novel family of fragment inhibitors of the enzyme ketosteroid isomerase displaying high values of enthalpic efficiency.

  • Organizational Affiliation

    Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Steroid Delta-isomerase
A, B
132Pseudomonas putidaMutation(s): 0 
Gene Names: ksi
Find proteins for P07445 (Pseudomonas putida)
Explore P07445 
Go to UniProtKB:  P07445
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP07445
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.50 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.150 
  • R-Value Observed: 0.152 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 35.563α = 90
b = 73.353β = 90
c = 95.549γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PDB_EXTRACTdata extraction
SERGUIdata collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-02-27
    Type: Initial release
  • Version 1.1: 2013-08-21
    Changes: Database references
  • Version 1.2: 2017-11-22
    Changes: Refinement description
  • Version 1.3: 2023-11-08
    Changes: Data collection, Database references, Derived calculations, Refinement description