7L5R image
Entry Detail
PDB ID:
7L5R
Keywords:
Title:
Crystal Structure of the Oxacillin-hydrolyzing Class D Extended-spectrum Beta-lactamase OXA-14 from Pseudomonas aeruginosa
Biological Source:
Source Organism:
PDB Version:
Deposition Date:
2020-12-22
Release Date:
2021-12-29
Method Details:
Experimental Method:
Resolution:
1.65 Å
R-Value Free:
0.19
R-Value Work:
0.16
R-Value Observed:
0.16
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Beta-lactamase
Chain IDs:A
Chain Length:248
Number of Molecules:1
Biological Source:Pseudomonas aeruginosa
Polymer Type:polypeptide(L)
Description:Beta-lactamase
Chain IDs:B
Chain Length:248
Number of Molecules:1
Biological Source:Pseudomonas aeruginosa
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
KCX A LYS modified residue
Primary Citation
Functional and Structural Characterization of OXA-935, a Novel OXA-10-Family beta-Lactamase from Pseudomonas aeruginosa.
Antimicrob.Agents Chemother. 66 e0098522 e0098522 (2022)
PMID: 36129295 DOI: 10.1128/aac.00985-22

Abstact

Resistance to antipseudomonal penicillins and cephalosporins is often driven by the overproduction of the intrinsic β-lactamase AmpC. However, OXA-10-family β-lactamases are a rich source of resistance in Pseudomonas aeruginosa. OXA β-lactamases have a propensity for mutation that leads to extended spectrum cephalosporinase and carbapenemase activity. In this study, we identified isolates from a subclade of the multidrug-resistant (MDR) high risk P. aeruginosa clonal complex CC446 with a resistance to ceftazidime. A genomic analysis revealed that these isolates harbored a plasmid containing a novel allele of blaOXA-10, named blaOXA-935, which was predicted to produce an OXA-10 variant with two amino acid substitutions: an aspartic acid instead of a glycine at position 157 and a serine instead of a phenylalanine at position 153. The G157D mutation, present in OXA-14, is associated with the resistance of P. aeruginosa to ceftazidime. Compared to OXA-14, OXA-935 showed increased catalytic efficiency for ceftazidime. The deletion of blaOXA-935 restored the sensitivity to ceftazidime, and susceptibility profiling of P. aeruginosa laboratory strains expressing blaOXA-935 revealed that OXA-935 conferred ceftazidime resistance. To better understand the impacts of the variant amino acids, we determined the crystal structures of OXA-14 and OXA-935. Compared to OXA-14, the F153S mutation in OXA-935 conferred increased flexibility in the omega (Ω) loop. Amino acid changes that confer extended spectrum cephalosporinase activity to OXA-10-family β-lactamases are concerning, given the rising reliance on novel β-lactam/β-lactamase inhibitor combinations, such as ceftolozane-tazobactam and ceftazidime-avibactam, to treat MDR P. aeruginosa infections.

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Primary Citation of related structures