2GDN

Crystal structure of the Mycobacterium tuberculosis beta-lactamase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.72 Å
  • R-Value Free: 0.213 
  • R-Value Work: 0.180 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Crystal Structure and Activity Studies of the Mycobacterium tuberculosis {beta}-Lactamase Reveal Its Critical Role in Resistance to {beta}-Lactam Antibiotics.

Wang, F.Cassidy, C.Sacchettini, J.C.

(2006) Antimicrob.Agents Chemother. 50: 2762-2771

  • DOI: 10.1128/AAC.00320-06

  • PubMed Abstract: 
  • beta-Lactam antibiotics are extremely effective in disrupting the synthesis of the bacterial cell wall in both gram-positive and gram-negative bacteria. However, they are ineffective against Mycobacterium tuberculosis, due to the production of a beta ...

    beta-Lactam antibiotics are extremely effective in disrupting the synthesis of the bacterial cell wall in both gram-positive and gram-negative bacteria. However, they are ineffective against Mycobacterium tuberculosis, due to the production of a beta-lactamase enzyme encoded on the chromosome of M. tuberculosis that degrades these antibiotics. Indeed, recent studies have demonstrated that deletion of the blaC gene, the only gene encoding a beta-lactamase in M. tuberculosis, or inhibition of the encoded enzyme resulted in significantly increased sensitivity to beta-lactam antibiotics. In this paper we present a biochemical and structural characterization of M. tuberculosis BlaC. Recombinant BlaC shows a broad range of specificity with almost equal penicillinase and cepholothinase activity. While clavulanate is a mechanism-based inhibitor to class A beta-lactamase with high potency (typically K(i) < 0.1 microM), it is a relatively poor inhibitor of the M. tuberculosis BlaC (K(i) = 2.4 microM). The crystal structure of the enzyme, determined at a resolution of 1.7 A, shows that the overall fold of the M. tuberculosis enzyme is similar to other class A beta-lactamases. There are, however, several distinct features of the active site, such as the amino acid substitutions N132G, R164A, R244A, and R276E, that explain the broad specificity of the enzyme, relatively low penicillinase activity, and resistance to clavulanate.


    Organizational Affiliation

    Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Beta-lactamase
A
267Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)Mutation(s): 0 
Gene Names: blaC (blaA)
EC: 3.5.2.6
Find proteins for P9WKD3 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Go to UniProtKB:  P9WKD3
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.72 Å
  • R-Value Free: 0.213 
  • R-Value Work: 0.180 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 42.744α = 90.00
b = 71.283β = 90.00
c = 85.169γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
PDB_EXTRACTdata extraction
ADSCdata collection
REFMACrefinement
MOLREPphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-04-18
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-18
    Type: Refinement description