6H2A

Structure of S70A BlaC from Mycobacterium tuberculosis obtained from crystals produced in the presence of DTT


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.54 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.228 
  • R-Value Observed: 0.229 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.2 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: https://doi.org/10.1021/acs.biochem.8b01085
  • Primary Citation of Related Structures:  
    6H27, 6H28, 6H2A, 6H2C, 6H2G, 6H2H, 6H2I, 6H2K

  • 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 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:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Beta-lactamase
A, B, C
274Mycobacterium tuberculosisMutation(s): 1 
Gene Names: blaCERS027646_02769
EC: 3.5.2.6
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
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  • Reference Sequence

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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Possible protein degradation productD [auth H]6Mycobacterium tuberculosisMutation(s): 0 
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
TAM
Query on TAM

Download Ideal Coordinates CCD File 
E [auth A],
J [auth A]
TRIS(HYDROXYETHYL)AMINOMETHANE
C7 H17 N O3
GKODZWOPPOTFGA-UHFFFAOYSA-N
DTT
Query on DTT

Download Ideal Coordinates CCD File 
F [auth A],
L [auth B],
M [auth B],
R [auth C]
2,3-DIHYDROXY-1,4-DITHIOBUTANE
C4 H10 O2 S2
VHJLVAABSRFDPM-IMJSIDKUSA-N
PO4
Query on PO4

Download Ideal Coordinates CCD File 
G [auth A]
H [auth A]
I [auth A]
N [auth B]
O [auth B]
G [auth A],
H [auth A],
I [auth A],
N [auth B],
O [auth B],
S [auth C]
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
GOL
Query on GOL

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.54 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.228 
  • R-Value Observed: 0.229 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 108.864α = 90
b = 108.864β = 90
c = 260.577γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
Aimlessdata scaling
MOLREPphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-01-23
    Type: Initial release
  • Version 1.1: 2019-02-27
    Changes: Data collection, Database references
  • Version 1.2: 2024-01-17
    Changes: Advisory, Data collection, Database references, Refinement description