2ZYL

Crystal structure of 3-ketosteroid-9-alpha-hydroxylase (KshA) from M. tuberculosis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.197 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Characterization of 3-ketosteroid 9{alpha}-hydroxylase, a Rieske oxygenase in the cholesterol degradation pathway of Mycobacterium tuberculosis

Capyk, J.K.D'Angelo, I.Strynadka, N.C.Eltis, L.D.

(2009) J.Biol.Chem. 284: 9937-9946

  • DOI: 10.1074/jbc.M900719200

  • PubMed Abstract: 
  • KshAB (3-Ketosteroid 9alpha-hydroxylase) is a two-component Rieske oxygenase (RO) in the cholesterol catabolic pathway of Mycobacterium tuberculosis. Although the enzyme has been implicated in pathogenesis, it has largely been characterized by bioinf ...

    KshAB (3-Ketosteroid 9alpha-hydroxylase) is a two-component Rieske oxygenase (RO) in the cholesterol catabolic pathway of Mycobacterium tuberculosis. Although the enzyme has been implicated in pathogenesis, it has largely been characterized by bioinformatics and molecular genetics. Purified KshB, the reductase component, was a monomeric protein containing a plant-type [2Fe-2S] cluster and FAD. KshA, the oxygenase, was a homotrimer containing a Rieske [2Fe-2S] cluster and mononuclear ferrous iron. Of two potential substrates, reconstituted KshAB had twice the specificity for 1,4-androstadiene-3,17-dione as for 4-androstene-3,17-dione. The transformation of both substrates was well coupled to the consumption of O(2). Nevertheless, the reactivity of KshAB with O(2) was low in the presence of 1,4-androstadiene-3,17-dione, with a k(cat)/K(m)(O(2)) of 2450 +/- 80 m(-1) s(-1). The crystallographic structure of KshA, determined to 2.3A(,) revealed an overall fold and a head-to-tail subunit arrangement typical of ROs. The central fold of the catalytic domain lacks all insertions found in characterized ROs, consistent with a minimal and perhaps archetypical RO catalytic domain. The structure of KshA is further distinguished by a C-terminal helix, which stabilizes subunit interactions in the functional trimer. Finally, the substrate-binding pocket extends farther into KshA than in other ROs, consistent with the large steroid substrate, and the funnel accessing the active site is differently orientated. This study provides a solid basis for further studies of a key steroid-transforming enzyme of biotechnological and medical importance.


    Organizational Affiliation

    Departments of Biochemistry and Molecular Biology and Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver V6 1Z3, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
POSSIBLE OXIDOREDUCTASE
A
386Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)Mutation(s): 0 
Gene Names: kshA
Find proteins for P71875 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Go to UniProtKB:  P71875
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

Download SDF File 
Download CCD File 
A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
FES
Query on FES

Download SDF File 
Download CCD File 
A
FE2/S2 (INORGANIC) CLUSTER
Fe2 S2
NIXDOXVAJZFRNF-UHFFFAOYSA-N
 Ligand Interaction
FE2
Query on FE2

Download SDF File 
Download CCD File 
A
FE (II) ION
Fe
CWYNVVGOOAEACU-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.197 
  • Space Group: P 3 2 1
Unit Cell:
Length (Å)Angle (°)
a = 116.200α = 90.00
b = 116.200β = 90.00
c = 81.000γ = 120.00
Software Package:
Software NamePurpose
XDSdata reduction
REFMACrefinement
MxDCdata collection
XDSdata scaling
PHENIXphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-03-03
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance