4MBK

Crystal structure of K234R inhibitor-resistant variant of SHV beta-lactamase in complex with SA2-13


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.46 Å
  • R-Value Free: 
    0.214 (Depositor), 0.214 (DCC) 
  • R-Value Work: 
    0.178 (Depositor), 0.178 (DCC) 
  • R-Value Observed: 
    0.180 (Depositor) 

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 

Created with Raphaël 2.3.0Worse 01 BetterLigand structure goodness of fit to experimental dataBest fitted MA4Click on this verticalbar to view detailsBest fitted SA2Click on this verticalbar to view details

This is version 1.2 of the entry. See complete history


Literature

Penam sulfones and beta-lactamase inhibition: SA2-13 and the importance of the C2 side chain length and composition.

Rodkey, E.A.Winkler, M.L.Bethel, C.R.Pagadala, S.R.Buynak, J.D.Bonomo, R.A.van den Akker, F.

(2014) PLoS One 9: e85892-e85892

  • DOI: https://doi.org/10.1371/journal.pone.0085892
  • Primary Citation of Related Structures:  
    4MBF, 4MBH, 4MBK

  • PubMed Abstract: 

    β-Lactamases are the major reason β-lactam resistance is seen in Gram-negative bacteria. To combat this resistance mechanism, β-lactamase inhibitors are currently being developed. Presently, there are only three that are in clinical use (clavulanate, sulbactam and tazobactam). In order to address this important medical need, we explored a new inhibition strategy that takes advantage of a long-lived inhibitory trans-enamine intermediate. SA2-13 was previously synthesized and shown to have a lower k(react) than tazobactam. We investigated here the importance of the carboxyl linker length and composition by synthesizing three analogs of SA2-13 (PSR-4-157, PSR-4-155, and PSR-3-226). All SA2-13 analogs yielded higher turnover numbers and k(react) compared to SA2-13. We next demonstrated using protein crystallography that increasing the linker length by one carbon allowed for better capture of a trans-enamine intermediate; in contrast, this trans-enamine intermediate did not occur when the C2 linker length was decreased by one carbon. If the linker was altered by both shortening it and changing the carboxyl moiety into a neutral amide moiety, the stable trans-enamine intermediate in wt SHV-1 did not form; this intermediate could only be observed when a deacylation deficient E166A variant was studied. We subsequently studied SA2-13 against a relatively recently discovered inhibitor-resistant (IR) variant of SHV-1, SHV K234R. Despite the alteration in the mechanism of resistance due to the K→R change in this variant, SA2-13 was effective at inhibiting this IR enzyme and formed a trans-enamine inhibitory intermediate similar to the intermediate seen in the wt SHV-1 structure. Taken together, our data reveals that the C2 side chain linker length and composition profoundly affect the formation of the trans-enamine intermediate of penam sulfones. We also show that the design of SA2-13 derivatives offers promise against IR SHV β-lactamases that possess the K234R substitution.


  • Organizational Affiliation

    Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, United States of America.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Beta-lactamase SHV-1265Klebsiella pneumoniaeMutation(s): 1 
Gene Names: blashv1
EC: 3.5.2.6
UniProt
Find proteins for P0AD64 (Klebsiella pneumoniae)
Explore P0AD64 
Go to UniProtKB:  P0AD64
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0AD64
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.46 Å
  • R-Value Free:  0.214 (Depositor), 0.214 (DCC) 
  • R-Value Work:  0.178 (Depositor), 0.178 (DCC) 
  • R-Value Observed: 0.180 (Depositor) 
Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 49.212α = 90
b = 55.361β = 90
c = 83.325γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 

Created with Raphaël 2.3.0Worse 01 BetterLigand structure goodness of fit to experimental dataBest fitted MA4Click on this verticalbar to view detailsBest fitted SA2Click on this verticalbar to view details

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-07-30
    Type: Initial release
  • Version 1.1: 2017-11-15
    Changes: Refinement description
  • Version 1.2: 2024-11-06
    Changes: Data collection, Database references, Derived calculations, Structure summary