6H27

Structure of S70C BlaC from Mycobacterium tuberculosis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.63 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.234 
  • R-Value Observed: 0.236 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

New Conformations of Acylation Adducts of Inhibitors of beta-Lactamase from Mycobacterium tuberculosis.

Tassoni, R.Blok, A.Pannu, N.S.Ubbink, M.

(2019) Biochemistry 58: 997-1009

  • DOI: 10.1021/acs.biochem.8b01085
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Mycobacterium tuberculosis (Mtb), the main causative agent of tuberculosis (TB), is naturally resistant to β-lactam antibiotics due to the production of the extended spectrum β-lactamase BlaC. β-Lactam/β-lactamase inhibitor combination therapies can ...

    Mycobacterium tuberculosis (Mtb), the main causative agent of tuberculosis (TB), is naturally resistant to β-lactam antibiotics due to the production of the extended spectrum β-lactamase BlaC. β-Lactam/β-lactamase inhibitor combination therapies can circumvent the BlaC-mediated resistance of Mtb and are promising treatment options against TB. However, still little is known of the exact mechanism of BlaC inhibition by the β-lactamase inhibitors currently approved for clinical use, clavulanic acid, sulbactam, tazobactam, and avibactam. Here, we present the X-ray diffraction crystal structures of the acyl-enzyme adducts of wild-type BlaC with the four inhibitors. The +70 Da adduct derived from clavulanate and the trans-enamine acylation adducts of sulbactam and tazobactam are reported. BlaC in complex with avibactam revealed two inhibitor conformations. Preacylation binding could not be observed because inhibitor binding was not detected in BlaC variants carrying a substitution of the active site serine 70 to either alanine or cysteine, by crystallography, ITC or NMR. These results suggest that the catalytic serine 70 is necessary not only for enzyme acylation but also for increasing BlaC affinity for inhibitors in the preacylation state. The structure of BlaC with the serine to cysteine mutation showed a covalent linkage of the cysteine 70 Sγ atom to the nearby amino group of lysine 73. The differences of adduct conformations between BlaC and other β-lactamases are discussed.


    Organizational Affiliation

    Leiden Institute of Chemistry , Leiden University , Einsteinweg 55 , Leiden 2333CC , The Netherlands.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
BlaCA, B274Mycobacterium tuberculosisMutation(s): 1 
EC: 3.5.2.6
Find proteins for P0A5I7 (Mycobacterium bovis (strain ATCC BAA-935 / AF2122/97))
Explore P0A5I7 
Go to UniProtKB:  P0A5I7
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PG0
Query on PG0

Download CCD File 
A, B
2-(2-METHOXYETHOXY)ETHANOL
C5 H12 O3
SBASXUCJHJRPEV-UHFFFAOYSA-N
 Ligand Interaction
EDO
Query on EDO

Download CCD File 
A
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.63 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.234 
  • R-Value Observed: 0.236 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 39.6α = 90
b = 76.41β = 90.7
c = 79.32γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
Aimlessdata scaling
MOLREPphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2019-01-23
    Type: Initial release
  • Version 1.1: 2019-02-27
    Changes: Data collection, Database references