7LLH

KPC-2 F72Y mutant with acylated imipenem


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.219 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.184 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.4 of the entry. See complete history


Literature

Local interactions with the Glu166 base and the conformation of an active site loop play key roles in carbapenem hydrolysis by the KPC-2 beta-lactamase.

Furey, I.M.Mehta, S.C.Sankaran, B.Hu, L.Prasad, B.V.V.Palzkill, T.

(2021) J Biol Chem 296: 100799-100799

  • DOI: https://doi.org/10.1016/j.jbc.2021.100799
  • Primary Citation of Related Structures:  
    7LJK, 7LK8, 7LLB, 7LLH, 7LNL

  • PubMed Abstract: 

    The Klebsiella pneumoniae carbapenemase-2 (KPC-2) is a common source of antibiotic resistance in Gram-negative bacterial infections. KPC-2 is a class A β-lactamase that exhibits a broad substrate profile and hydrolyzes most β-lactam antibiotics including carbapenems owing to rapid deacylation of the covalent acyl-enzyme intermediate. However, the features that allow KPC-2 to deacylate substrates more rapidly than non-carbapenemase enzymes are not clear. The active-site residues in KPC-2 are largely conserved in sequence and structure compared with non-carbapenemases, suggesting that subtle alterations may collectively facilitate hydrolysis of carbapenems. We utilized a nonbiased genetic approach to identify mutants deficient in carbapenem hydrolysis but competent for ampicillin hydrolysis. Subsequent pre-steady-state enzyme kinetics analyses showed that the substitutions slow the rate of deacylation of carbapenems. Structure determination via X-ray diffraction indicated that a F72Y mutant forms a hydrogen bond between the tyrosine hydroxyl group and Glu166, which may lower basicity and impair the activation of the catalytic water for deacylation, whereas several mutants impact the structure of the Q214-R220 active site loop. A T215P substitution lowers the deacylation rate and drastically alters the conformation of the loop, thereby disrupting interactions between the enzyme and the carbapenem acyl-enzyme intermediate. Thus, the environment of the Glu166 general base and the precise placement and conformational stability of the Q214-R220 loop are critical for efficient deacylation of carbapenems by the KPC-2 enzyme. Therefore, the design of carbapenem antibiotics that interact with Glu166 or alter the Q214-R220 loop conformation may disrupt enzyme function and overcome resistance.


  • Organizational Affiliation

    Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Carbapenem-hydrolyzing beta-lactamase KPC
A, B
260Klebsiella pneumoniaeMutation(s): 1 
Gene Names: blakpckpc1
EC: 3.5.2.6
UniProt
Find proteins for Q9F663 (Klebsiella pneumoniae)
Explore Q9F663 
Go to UniProtKB:  Q9F663
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9F663
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
IM2 (Subject of Investigation/LOI)
Query on IM2

Download Ideal Coordinates CCD File 
C [auth A],
D [auth B]
(5R)-5-[(1S,2R)-1-formyl-2-hydroxypropyl]-3-[(2-{[(E)-iminomethyl]amino}ethyl)sulfanyl]-4,5-dihydro-1H-pyrrole-2-carbox ylic acid
C12 H19 N3 O4 S
UACUABDJLSUFFC-IWSPIJDZSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.219 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.184 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 34.609α = 88.118
b = 37.123β = 88.375
c = 83.655γ = 85.479
Software Package:
Software NamePurpose
PHENIXrefinement
xia2data reduction
pointlessdata scaling
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)United StatesAI32956

Revision History  (Full details and data files)

  • Version 1.0: 2021-05-26
    Type: Initial release
  • Version 1.1: 2021-06-02
    Changes: Database references
  • Version 1.2: 2021-06-30
    Changes: Structure summary
  • Version 1.3: 2021-07-21
    Changes: Database references
  • Version 1.4: 2023-10-18
    Changes: Data collection, Database references, Refinement description