2IPF

Crystal structure of 17alpha-hydroxysteroid dehydrogenase in complex with NADP+ and epi-testosterone


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.171 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Mouse 17alpha-Hydroxysteroid Dehydrogenase (AKR1C21) Binds Steroids Differently from other Aldo-keto Reductases: Identification and Characterization of Amino Acid Residues Critical for Substrate Binding.

Faucher, F.Cantin, L.Pereira de Jesus-Tran, K.Lemieux, M.Luu-The, V.Labrie, F.Breton, R.

(2007) J.Mol.Biol. 369: 525-540

  • DOI: 10.1016/j.jmb.2007.03.058
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The mouse 17alpha-hydroxysteroid dehydrogenase (m17alpha-HSD) is the unique known member of the aldo-keto reductase (AKR) superfamily able to catalyze efficiently and in a stereospecific manner the conversion of androstenedione (Delta4) into epi-test ...

    The mouse 17alpha-hydroxysteroid dehydrogenase (m17alpha-HSD) is the unique known member of the aldo-keto reductase (AKR) superfamily able to catalyze efficiently and in a stereospecific manner the conversion of androstenedione (Delta4) into epi-testosterone (epi-T), the 17alpha-epimer of testosterone. Structural and mutagenic studies had already identified one of the residues delineating the steroid-binding cavity, A24, as the major molecular determinant for the stereospecificity of m17alpha-HSD. We report here a ternary complex crystal structure (m17alpha-HSD:NADP(+):epi-T) determined at 1.85 A resolution that confirms this and reveals a unique steroid-binding mode for an AKR enzyme. Indeed, in addition to the interactions found in all other AKRs (van der Waals contacts stabilizing the core of the steroid and the hydrogen bonds established at the catalytic site by the Y55 and H117 residues with the oxygen atom of the ketone group to be reduced), m17alpha-HSD establishes with the other extremity of the steroid nucleus an additional interaction involving K31. By combining direct mutagenesis and kinetic studies, we found that the elimination of this hydrogen bond did not affect the affinity of the enzyme for its steroid substrate but led to a slight but significant increase of its catalytic efficiency (k(cat)/K(m)), suggesting a role for K31 in the release of the steroidal product at the end of the reaction. This previously unobserved steroid-binding mode for an AKR is similar to that adopted by other steroid-binding proteins, the hydroxysteroid dehydrogenases of the short-chain dehydrogenases/reductases (SDR) family and the steroid hormone nuclear receptors. Mutagenesis and structural studies made on the human type 3 3alpha-HSD, a closely related enzyme that shares 73% amino acids identity with the m17alpha-HSD, also revealed that the residue at position 24 of these two enzymes directly affects the binding and/or the release of NADPH, in addition to its role in their 17alpha/17beta stereospecificity.


    Organizational Affiliation

    Oncology and Molecular Endocrinology Research Center, Laval University Medical Center (CHUL), Laval University, Qu├ębec, Canada G1V 4G2.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
(3(17)alpha-hydroxysteroid dehydrogenase)
A, B
318Mus musculusMutation(s): 0 
Gene Names: Akr1c21
EC: 1.1.1.-
Find proteins for Q91WR5 (Mus musculus)
Go to UniProtKB:  Q91WR5
Small Molecules
Ligands 5 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

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

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Download CCD File 
A, B
BETA-MERCAPTOETHANOL
C2 H6 O S
DGVVWUTYPXICAM-UHFFFAOYSA-N
 Ligand Interaction
FFA
Query on FFA

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Download CCD File 
A, B
(10ALPHA,13ALPHA,14BETA,17ALPHA)-17-HYDROXYANDROST-4-EN-3-ONE
EPI-TESTOSTERONE
C19 H28 O2
MUMGGOZAMZWBJJ-KZYORJDKSA-N
 Ligand Interaction
TRS
Query on TRS

Download SDF File 
Download CCD File 
A
2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL
TRIS BUFFER
C4 H12 N O3
LENZDBCJOHFCAS-UHFFFAOYSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.171 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 49.230α = 90.00
b = 97.400β = 99.26
c = 79.460γ = 90.00
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
CrystalCleardata collection
CNSrefinement
XDSdata reduction
XSCALEdata scaling
XSCALEdata processing
MOLREPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-06-19
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2012-05-16
    Type: Other