3ZHH

X-ray structure of the full-length beta-lactamase from M.tuberculosis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.168 
  • R-Value Observed: 0.170 

wwPDB Validation 3D Report Full Report



Literature

Directed Evolution of Mycobacterium Tuberculosis Beta-Lactamase Reveals Gatekeeper Residue that Regulates Antibiotic Resistance and Catalytic Efficiency.

Feiler, C.Fisher, A.C.Boock, J.T.Marrichi, M.J.Wright, L.Schmidpeter, P.A.M.Blankenfeldt, W.Pavelka, M.Delisa, M.P.

(2013) PLoS One 8: 73123

  • DOI: 10.1371/journal.pone.0073123
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Directed evolution can be a powerful tool for revealing the mutational pathways that lead to more resistant bacterial strains. In this study, we focused on the bacterium Mycobacterium tuberculosis, which is resistant to members of the β-lactam class ...

    Directed evolution can be a powerful tool for revealing the mutational pathways that lead to more resistant bacterial strains. In this study, we focused on the bacterium Mycobacterium tuberculosis, which is resistant to members of the β-lactam class of antibiotics and thus continues to pose a major public health threat. Resistance of this organism is the result of a chromosomally encoded, extended spectrum class A β-lactamase, BlaC, that is constitutively produced. Here, combinatorial enzyme libraries were selected on ampicillin to identify mutations that increased resistance of bacteria to β-lactams. After just a single round of mutagenesis and selection, BlaC mutants were evolved that conferred 5-fold greater antibiotic resistance to cells and enhanced the catalytic efficiency of BlaC by 3-fold compared to the wild-type enzyme. All isolated mutants carried a mutation at position 105 (e.g., I105F) that appears to widen access to the active site by 3.6 Å while also stabilizing the reorganized topology. In light of these findings, we propose that I105 is a 'gatekeeper' residue of the active site that regulates substrate hydrolysis by BlaC. Moreover, our results suggest that directed evolution can provide insight into the development of highly drug resistant microorganisms.


    Organizational Affiliation

    School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York, United States of America.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
BETA-LACTAMASEA, B, C, D276Mycobacterium tuberculosisMutation(s): 0 
EC: 3.5.2.6
Find proteins for P9WKD3 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Explore P9WKD3 
Go to UniProtKB:  P9WKD3
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download CCD File 
A, B, C, D
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.168 
  • R-Value Observed: 0.170 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 78.737α = 90
b = 96.438β = 108.48
c = 111.005γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XSCALEdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-09-25
    Type: Initial release