2ZYL

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.199 

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
  • Primary Citation of Related Structures:  
    2ZYL

  • 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 bioinformatics and molecular genetics ...

    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:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
POSSIBLE OXIDOREDUCTASEA386Mycobacterium tuberculosisMutation(s): 0 
EC: 1.14.15.30
UniProt
Find proteins for P71875 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Explore P71875 
Go to UniProtKB:  P71875
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FES
Query on FES

Download Ideal Coordinates CCD File 
B [auth A]FE2/S2 (INORGANIC) CLUSTER
Fe2 S2
NIXDOXVAJZFRNF-UHFFFAOYSA-N
 Ligand Interaction
FE2
Query on FE2

Download Ideal Coordinates CCD File 
C [auth A]FE (II) ION
Fe
CWYNVVGOOAEACU-UHFFFAOYSA-N
 Ligand Interaction
NA
Query on NA

Download Ideal Coordinates CCD File 
D [auth A]SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.199 
  • Space Group: P 3 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 116.2α = 90
b = 116.2β = 90
c = 81γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
MxDCdata collection
XDSdata reduction
XDSdata scaling
PHENIXphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

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