3CAS

Crystal structure of 5beta-reductase (AKR1D1) in complex with NADP+ and 4-androstenedione


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.208 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal Structures of Human Delta4-3-Ketosteroid 5beta-Reductase (AKR1D1) Reveal the Presence of an Alternative Binding Site Responsible for Substrate Inhibition (dagger) (,) (double dagger).

Faucher, F.Cantin, L.Luu-The, V.Labrie, F.Breton, R.

(2008) Biochemistry 47: 13537-13546

  • DOI: 10.1021/bi801276h
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The 5beta-reductases (AKR1D1-3) are unique enzymes able to catalyze efficiently and in a stereospecific manner the 5beta-reduction of the C4-C5 double bond found in Delta4-3-ketosteroids, including steroid hormones and bile acids precursors such as 7 ...

    The 5beta-reductases (AKR1D1-3) are unique enzymes able to catalyze efficiently and in a stereospecific manner the 5beta-reduction of the C4-C5 double bond found in Delta4-3-ketosteroids, including steroid hormones and bile acids precursors such as 7alpha-hydroxy-4-cholesten-3-one and 7alpha,12alpha-dihydroxy-4-cholesten-3-one. In order to elucidate the binding mode and substrate specificity in detail, biochemical and structural studies on human 5beta-reductase (h5beta-red; AKR1D1) have been recently undertaken. The crystal structure of a h5beta-red binary complex provides a complete picture of the NADPH-enzyme interactions involving the flexible loop B, which contributes to the maintenance of the cofactor in its binding site by acting as a "safety belt". Structural comparison with binary complexes of AKR1C enzymes, specifically the human type 3 3alpha-hydroxysteroid dehydrogenase (AKR1C2) and the mouse 17alpha-hydroxysteroid dehydrogenase (AKR1C21), also revealed particularities in loop B positioning that make the steroid-binding cavity of h5beta-red substantially larger than those of the two other enzymes. Kinetic characterization of the purified recombinant h5beta-red has shown that this enzyme exerts a strong activity toward progesterone (Prog) and androstenedione (Delta4) but is rapidly inhibited by these substrates once their concentrations reach 2-times their K(m) value. A crystal structure of the h5beta-red in ternary complex with NADPH and Delta4 has revealed that the large steroid-binding site of this enzyme also contains a subsite in which the Delta4 molecule is found. When bound in this subsite, Delta4 completely impedes the passage of another substrate molecule toward the catalytic site. The importance of this alternative binding site for the inhibition of h5beta-red was finally proven by site-directed mutagenesis, which demonstrated that the replacement of one of the residues delineating this site (Val(309)) by a phenylalanine completely abolishes the substrate inhibition. The results of this report provide structural insights into the substrate inhibition of h5beta-red by C19- and C21-steroids.


    Organizational Affiliation

    Oncology and Molecular Endocrinology Research Center, Laval University Medical Center (CHUL) and Laval University, Laval, Quebec (QC) G1V 4G2, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
3-oxo-5-beta-steroid 4-dehydrogenase
A, B
326Homo sapiensMutation(s): 0 
Gene Names: AKR1D1 (SRD5B1)
EC: 1.3.1.3
Find proteins for P51857 (Homo sapiens)
Go to Gene View: AKR1D1
Go to UniProtKB:  P51857
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAP
Query on NAP

Download SDF File 
Download CCD File 
A, B
NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE
2'-MONOPHOSPHOADENOSINE 5'-DIPHOSPHORIBOSE
C21 H28 N7 O17 P3
XJLXINKUBYWONI-NNYOXOHSSA-N
 Ligand Interaction
EDO
Query on EDO

Download SDF File 
Download CCD File 
A, B
1,2-ETHANEDIOL
ETHYLENE GLYCOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
BME
Query on BME

Download SDF File 
Download CCD File 
A
BETA-MERCAPTOETHANOL
C2 H6 O S
DGVVWUTYPXICAM-UHFFFAOYSA-N
 Ligand Interaction
ASD
Query on ASD

Download SDF File 
Download CCD File 
A, B
4-ANDROSTENE-3-17-DIONE
C19 H26 O2
AEMFNILZOJDQLW-QAGGRKNESA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.208 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 50.410α = 90.00
b = 110.870β = 90.00
c = 130.280γ = 90.00
Software Package:
Software NamePurpose
XDSdata reduction
XSCALEdata scaling
MOLREPphasing
PDB_EXTRACTdata extraction
CNSrefinement
CrystalCleardata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-12-09
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2018-01-24
    Type: Structure summary