Cryo-EM structure of W107R KatG from M. tuberculosis

Experimental Data Snapshot

  • Resolution: 3.30 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

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Using cryo-EM to understand antimycobacterial resistance in the catalase-peroxidase (KatG) from Mycobacterium tuberculosis.

Munir, A.Wilson, M.T.Hardwick, S.W.Chirgadze, D.Y.Worrall, J.A.R.Blundell, T.L.Chaplin, A.K.

(2021) Structure 29: 899-912.e4

  • DOI: https://doi.org/10.1016/j.str.2020.12.008
  • Primary Citation of Related Structures:  
    7A2I, 7A7A, 7A7C, 7A8Z, 7AA3, 7AG8

  • PubMed Abstract: 

    Resolution advances in cryoelectron microscopy (cryo-EM) now offer the possibility to visualize structural effects of naturally occurring resistance mutations in proteins and also of understanding the binding mechanisms of small drug molecules. In Mycobacterium tuberculosis the multifunctional heme enzyme KatG is indispensable for activation of isoniazid (INH), a first-line pro-drug for treatment of tuberculosis. We present a cryo-EM methodology for structural and functional characterization of KatG and INH resistance variants. The cryo-EM structure of the 161 kDa KatG dimer in the presence of INH is reported to 2.7 Å resolution allowing the observation of potential INH binding sites. In addition, cryo-EM structures of two INH resistance variants, identified from clinical isolates, W107R and T275P, are reported. In combination with electronic absorbance spectroscopy our cryo-EM approach reveals how these resistance variants cause disorder in the heme environment preventing heme uptake and retention, providing insight into INH resistance.

  • Organizational Affiliation

    CryoEM Facility, Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
740Mycobacterium tuberculosisMutation(s): 1 
Gene Names: katGERS007661_00994ERS013471_02729ERS024276_01596ERS075361_01376ERS094182_01139F6W99_00474FRD82_12135
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
HEM (Subject of Investigation/LOI)
Query on HEM

Download Ideal Coordinates CCD File 
C34 H32 Fe N4 O4
Experimental Data & Validation

Experimental Data

  • Resolution: 3.30 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Bill & Melinda Gates FoundationUnited KingdomRG 86546

Revision History  (Full details and data files)

  • Version 1.0: 2021-01-27
    Type: Initial release
  • Version 1.1: 2021-08-18
    Changes: Database references