1E3V

Crystal structure of ketosteroid isomerase from Psedomonas putida complexed with deoxycholate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.198 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Detection of Large Pka Perturbations of an Inhibitor and a Catalytic Group at an Enzyme Active Site, a Mechanistic Basis for Catalytic Power of Many Enzymes

Ha, N.-C.Kim, M.-S.Lee, W.Choi, K.Y.Oh, B.-H.

(2000) J.Biol.Chem. 275: 41100

  • DOI: 10.1074/jbc.M007561200
  • Primary Citation of Related Structures:  1E3R, 1OGX

  • PubMed Abstract: 
  • Delta(5)-3-Ketosteroid isomerase catalyzes cleavage and formation of a C-H bond at a diffusion-controlled limit. By determining the crystal structures of the enzyme in complex with each of three different inhibitors and by nuclear magnetic resonance ...

    Delta(5)-3-Ketosteroid isomerase catalyzes cleavage and formation of a C-H bond at a diffusion-controlled limit. By determining the crystal structures of the enzyme in complex with each of three different inhibitors and by nuclear magnetic resonance (NMR) spectroscopic investigation, we evidenced the ionization of a hydroxyl group (pK(a) approximately 16.5) of an inhibitor, which forms a low barrier hydrogen bond (LBHB) with a catalytic residue Tyr(14) (pK(a) approximately 11.5), and the protonation of the catalytic residue Asp(38) with pK(a) of approximately 4.5 at pH 6.7 in the interaction with a carboxylate group of an inhibitor. The perturbation of the pK(a) values in both cases arises from the formation of favorable interactions between inhibitors and catalytic residues. The results indicate that the pK(a) difference between catalytic residue and substrate can be significantly reduced in the active site environment as a result of the formation of energetically favorable interactions during the course of enzyme reactions. The reduction in the pK(a) difference should facilitate the abstraction of a proton and thereby eliminate a large fraction of activation energy in general acid/base enzyme reactions. The pK(a) perturbation provides a mechanistic ground for the fast reactivity of many enzymes and for the understanding of how some enzymes are able to extract a proton from a C-H group with a pK(a) value as high as approximately 30.


    Organizational Affiliation

    National Creative Research Initiative Center for Biomolecular Recognition, Department of Life Science and Division of Molecular and Life Science, Pohang University of Science and Technology, Pohang, Kyungbuk 790-784, Korea.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
STEROID DELTA-ISOMERASE
A, B
131Pseudomonas putidaGene Names: ksi
EC: 5.3.3.1
Find proteins for P07445 (Pseudomonas putida)
Go to UniProtKB:  P07445
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
DXC
Query on DXC

Download SDF File 
Download CCD File 
A, B
(3ALPHA,5BETA,12ALPHA)-3,12-DIHYDROXYCHOLAN-24-OIC ACID
DEOXYCHOLIC ACID
C24 H40 O4
KXGVEGMKQFWNSR-LLQZFEROSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
DHOKd: 16000 nM (100) BINDINGDB
DXCKd: 45740 nM BINDINGMOAD
DXCKd: 45740 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.198 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 36.580α = 90.00
b = 75.210β = 90.00
c = 96.130γ = 90.00
Software Package:
Software NamePurpose
X-PLORrefinement
SCALEPACKdata scaling
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-03-12
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance