4BHC

CRYSTAL STRUCTURE OF THE M. TUBERCULOSIS O6-METHYLGUANINE METHYLTRANSFERASE R37L VARIANT


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.176 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Biochemical and Structural Studies on the M. 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:  

  • 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 counte ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
METHYLATED-DNA--PROTEIN-CYSTEINE METHYLTRANSFERASE
A
165Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)Mutation(s): 2 
Gene Names: ogt
EC: 2.1.1.63
Find proteins for P9WJW5 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Go to UniProtKB:  P9WJW5
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.176 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 59.116α = 90.00
b = 82.854β = 90.00
c = 37.908γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
SCALAdata scaling
MOSFLMdata reduction
PHENIXphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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