Crystal structure of the catalase-peroxidase (KatG) and S315T mutant from Mycobacterium tuberculosis

Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.200 

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Hydrogen Peroxide-Mediated Isoniazid Activation Catalyzed by Mycobacterium Tuberculosis Catalase-Peroxidase (Katg) and its S315T Mutant.

Zhao, X.Yu, H.Yu, S.Wang, F.Sacchettini, J.C.Magliozzo, R.S.

(2006) Biochemistry 45: 4131

  • DOI: https://doi.org/10.1021/bi051967o
  • Primary Citation of Related Structures:  
    2CCA, 2CCD

  • PubMed Abstract: 

    Inhibition of the enzyme Mycobacterium tuberculosis InhA (enoyl-acyl carrier protein reductase) due to formation of an isonicotinoyl-NAD adduct (IN-NAD) from isoniazid (INH) and nicotinamide adenine dinucleotide cofactor is considered central to the mode of action of INH, a first-line treatment for tuberculosis infection. INH action against mycobacteria requires catalase-peroxidase (KatG) function, and IN-NAD adduct formation is catalyzed in vitro by M. tuberculosis KatG under a variety of conditions, yet a physiologically relevant approach to the process has not emerged that allows scrutiny of the mechanism and the origins of INH resistance in the most prevalent drug-resistant strain bearing KatG[S315T]. In this report, we describe how hydrogen peroxide, delivered at very low concentrations to ferric KatG, leads to efficient inhibition of InhA due to formation of the IN-NAD adduct. The rate of adduct formation mediated by wild-type KatG was about 20-fold greater than by the isoniazid-resistant KatG[S315T] mutant under optimal conditions (H2O2 supplied along with NAD+ and INH). Slow adduct formation also occurs starting with NADH and INH, in the presence of KatG even in the absence of added peroxide, due to endogenous peroxide. The poor efficiency of the KatG[S315T] mutant can be enhanced merely by increasing the concentration of INH, consistent with this enzyme's reduced affinity for INH binding to the resting enzyme and the catalytically competent enzyme intermediate (Compound I). Origins of drug resistance in the KatG[S315T] mutant enzyme are analyzed at the structural level through examination of the three-dimensional X-ray crystal structure of the mutant enzyme.

  • Organizational Affiliation

    Department of Chemistry, Brooklyn College, Brooklyn, New York 11210, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
740Mycobacterium tuberculosisMutation(s): 0 
Find proteins for P9WIE5 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Explore P9WIE5 
Go to UniProtKB:  P9WIE5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP9WIE5
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on HEM

Download Ideal Coordinates CCD File 
C [auth A],
D [auth B]
C34 H32 Fe N4 O4
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.200 
  • Space Group: P 42 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 150.104α = 90
b = 150.104β = 90
c = 153.718γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-01-19
    Type: Initial release
  • Version 1.1: 2014-01-15
    Changes: Derived calculations, Non-polymer description, Other, Version format compliance
  • Version 1.2: 2023-12-13
    Changes: Data collection, Database references, Derived calculations, Other, Refinement description