4BHB

Crystal structure of Mycobacterium tuberculosis O6-METHYLGUANINE METHYLTRANSFERASE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.294 
  • R-Value Work: 0.227 
  • R-Value Observed: 0.228 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Biochemical and Structural Studies of the Mycobacterium Tuberculosis O6-Methylguanine Methyltransferase and Mutated Variants.

Miggiano, R.Casazza, V.Garavaglia, S.Ciaramella, M.Perugino, G.Rizzi, M.Rossi, F.

(2013) J Bacteriol 195: 2728

  • DOI: 10.1128/JB.02298-12
  • Primary Citation of Related Structures:  
    4BHB, 4BHC

  • PubMed Abstract: 
  • Mycobacterium tuberculosis displays remarkable genetic stability despite continuous exposure to the hostile environment represented by the host's infected macrophages. Similarly to other organisms, M. tuberculosis possesses multiple systems to counteract the harmful potential of DNA alkylation ...

    Mycobacterium tuberculosis displays remarkable genetic stability despite continuous exposure to the hostile environment represented by the host's infected macrophages. Similarly to other organisms, M. tuberculosis possesses multiple systems to counteract the harmful potential of DNA alkylation. In particular, the suicidal enzyme O(6)-methylguanine-DNA methyltransferase (OGT) is responsible for the direct repair of O(6)-alkylguanine in double-stranded DNA and is therefore supposed to play a central role in protecting the mycobacterial genome from the risk of G · C-to-A · T transition mutations. Notably, a number of geographically widely distributed M. tuberculosis strains shows nonsynonymous single-nucleotide polymorphisms in their OGT-encoding gene, leading to amino acid substitutions at position 15 (T15S) or position 37 (R37L) of the N-terminal domain of the corresponding protein. However, the role of these mutations in M. tuberculosis pathogenesis is unknown. We describe here the in vitro characterization of M. tuberculosis OGT (MtOGT) and of two point-mutated versions of the protein mimicking the naturally occurring ones, revealing that both mutated proteins are impaired in their activity as a consequence of their lower affinity for alkylated DNA than the wild-type protein. The analysis of the crystal structures of MtOGT and MtOGT-R37L confirms the high level of structural conservation of members of this protein family and provides clues to an understanding of the molecular bases for the reduced affinity for the natural substrate displayed by mutated MtOGT. Our in vitro results could contribute to validate the inferred participation of mutated OGTs in M. tuberculosis phylogeny and biology.


    Organizational Affiliation

    Dipartimento di Scienze del Farmaco, University of Piemonte Orientale A Avogadro, Novara, Italy.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
METHYLATED-DNA--PROTEIN-CYSTEINE METHYLTRANSFERASEA165Mycobacterium tuberculosis H37RvMutation(s): 1 
Gene Names: ogtRv1316cMTCY130.01c
EC: 2.1.1.63
UniProt
Find proteins for P9WJW5 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Explore P9WJW5 
Go to UniProtKB:  P9WJW5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP9WJW5
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download Ideal Coordinates CCD File 
B [auth A],
C [auth A]
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.294 
  • R-Value Work: 0.227 
  • R-Value Observed: 0.228 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 59.134α = 90
b = 81.752β = 90
c = 38.165γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
MOSFLMdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-04-17
    Type: Initial release
  • Version 1.1: 2013-06-12
    Changes: Database references