1IHI

Crystal Structure of Human Type III 3-alpha-Hydroxysteroid Dehydrogenase/Bile Acid Binding Protein (AKR1C2) Complexed with NADP+ and Ursodeoxycholate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3 Å
  • R-Value Free: 0.278 
  • R-Value Work: 0.223 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of human type III 3alpha-hydroxysteroid dehydrogenase/bile acid binding protein complexed with NADP(+) and ursodeoxycholate.

Jin, Y.Stayrook, S.E.Albert, R.H.Palackal, N.T.Penning, T.M.Lewis, M.

(2001) Biochemistry 40: 10161-10168


  • PubMed Abstract: 
  • The crystal structure of human type III 3alpha-hydroxysteroid dehydrogenase (HSD)/bile acid binding protein (AKR1C2) complexed with NADP(+) and 3alpha,7beta-dihydroxy-5beta-cholanic acid (ursodeoxycholate) at 3.0 A resolution is presented. Thus, the ...

    The crystal structure of human type III 3alpha-hydroxysteroid dehydrogenase (HSD)/bile acid binding protein (AKR1C2) complexed with NADP(+) and 3alpha,7beta-dihydroxy-5beta-cholanic acid (ursodeoxycholate) at 3.0 A resolution is presented. Thus, the three-dimensional structure has now been solved for a human HSD member of the aldo-keto reductase superfamily. AKR1C2 is implicated in the prostatic production of the potent androgen 5alpha-dihydrotestosterone and the hepatic transport of bile acids. It also catalyzes the formation of the neurosteroid 3alpha-hydroxy-5alpha-pregnan-20-one in the central nervous system, and its allosteric modulation by fluoxetine has been linked to the use of this drug for premenstrual dsyphoria. Like other members of the superfamily, AKR1C2 folds into an alpha/beta-barrel and binds NADP(+) in an extended conformation. The carboxylate of ursodeoxycholate binds to AKR1C2 in the oxyanion hole at the active site. More interestingly, the orientation of ursodeoxycholate is essentially "backwards" and "upside-down" from that observed for testosterone in the related rat 3alpha-HSD.NADP(+).testosterone ternary complex, where testosterone assumes the position of a 3-ketosteroid substrate. The orientation of ursodeoxycholate is thus similar to that expected of a 17beta-HSD substrate. The ternary structure explains the ability of AKR1C2 to catalyze 3alpha-, 17beta-, and 20alpha-HSD reactions. Comparison of the steroid binding pocket of AKR1C2 with that of rat 3alpha-HSD reveals significant differences in the positions of conserved and nonconserved loop residues, providing insights into the structural basis for the functional flexibility that is observed in all the human 3alpha-HSD isoforms but not in the rat isoform.


    Organizational Affiliation

    Department of Pharmacology, Department of Biochemistry and Biophysics, and The Johnson Research Foundation, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
3-ALPHA-HYDROXYSTEROID DEHYDROGENASE
A, B
323Homo sapiensMutation(s): 0 
Gene Names: AKR1C2 (DDH2)
EC: 1.-.-.-
Find proteins for P52895 (Homo sapiens)
Go to Gene View: AKR1C2
Go to UniProtKB:  P52895
Small Molecules
Ligands 2 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
IU5
Query on IU5

Download SDF File 
Download CCD File 
A, B
ISO-URSODEOXYCHOLIC ACID
C24 H40 O4
RUDATBOHQWOJDD-DNMBCGTGSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3 Å
  • R-Value Free: 0.278 
  • R-Value Work: 0.223 
  • Space Group: H 3 2
Unit Cell:
Length (Å)Angle (°)
a = 144.090α = 90.00
b = 144.090β = 90.00
c = 202.770γ = 120.00
Software Package:
Software NamePurpose
AMoREphasing
DENZOdata reduction
SCALEPACKdata scaling
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-10-03
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance