9H2Z | pdb_00009h2z

Crystal structure of APH(2")-IVa alternate (soaking with EK3-18 inhibitor)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 
    0.292 (Depositor), 0.294 (DCC) 
  • R-Value Work: 
    0.208 (Depositor), 0.213 (DCC) 
  • R-Value Observed: 
    0.212 (Depositor) 

Starting Model: experimental
View more details

wwPDB Validation 3D Report Full Report

Validation slider image for 9H2Z

This is version 1.1 of the entry. See complete history

Literature

APH Inhibitors that Reverse Aminoglycoside Resistance in Enterococcus casseliflavus.

Kaplan, E.Chaloin, L.Guichou, J.F.Berrou, K.Rahimova, R.Labesse, G.Lionne, C.

(2025) ChemMedChem 20: e202400842-e202400842

  • DOI: https://doi.org/10.1002/cmdc.202400842
  • Primary Citation Related Structures: 
    9H2Z

  • PubMed Abstract: 

    Aminoglycoside-phosphotransferases (APHs) are a class of bacterial enzymes that mediate acquired resistance to aminoglycoside antibiotics. Here we report the identification of small molecules counteracting aminoglycoside resistance in Enterococcus casseliflavus. Molecular dynamics simulations were performed to identify an allosteric pocket in three APH enzymes belonging to 3' and 2'' subfamilies in which we then screened, in silico, 12,000 small molecules. From a subset of only 14 high-scored molecules tested in vitro, we identified a compound, named here EK3, able to non-competitively inhibit the APH(2'')-IVa, an enzyme mediating clinical gentamicin resistance. Structure-activity relationship (SAR) exploration of this hit compound allowed us to identify a molecule with improved enzymatic inhibition. By measuring bacterial sensitivity, we found that the three best compounds in this series restored bactericidal activity of various aminoglycosides, including gentamicin, without exhibiting toxicity to HeLa cells. This work not only provides a basis to fight aminoglycoside resistance but also highlights a proof-of-concept for the search of allosteric modulators by using in silico methods.


  • Organizational Affiliation
    • Institut de Recherche en Infectiologie de Montpellier - IRIM, University of Montpellier, CNRS UMR 9004, 1919 route de Mende, 34293, Montpellier cedex 5, France.

Macromolecule Content 

  • Total Structure Weight: 75.19 kDa 
  • Atom Count: 4,995 
  • Modeled Residue Count: 597 
  • Deposited Residue Count: 642 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
APH(2'')-Id
A, B
321Enterococcus casseliflavusMutation(s): 0 
Gene Names: aph(2'')-Id
UniProt
Find proteins for O68183 (Enterococcus casseliflavus)
Explore O68183 
Go to UniProtKB:  O68183
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO68183
Sequence Annotations
Expand
Reference Sequence

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free:  0.292 (Depositor), 0.294 (DCC) 
  • R-Value Work:  0.208 (Depositor), 0.213 (DCC) 
  • R-Value Observed: 0.212 (Depositor) 
Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.49α = 90
b = 63.01β = 92.74
c = 87.218γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
Aimlessdata scaling
PHASERphasing
autoPROCdata reduction

Structure Validation

View Full Validation Report



Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Agence Nationale de la Recherche (ANR)FranceANR-19-AMRB-0001

Revision History  (Full details and data files)

  • Version 1.0: 2025-02-05
    Type: Initial release
  • Version 1.1: 2025-04-30
    Changes: Database references