X-ray crystal structure of Acinetobacter baumanii beta-lactamase variant OXA-109 in complex with doripenemX-ray crystal structure of Acinetobacter baumanii beta-lactamase variant OXA-109 in complex with doripenem

Structural highlights

8sq8 is a 4 chain structure with sequence from Acinetobacter baumannii. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.27Å
Ligands:, ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

A8JZR7_ACIBA

Publication Abstract from PubMed

OXA-66 is a member of the OXA-51 subfamily of class D beta-lactamases native to the Acinetobacter genus that includes Acinetobacter baumannii, one of the ESKAPE pathogens and a major cause of drug-resistant nosocomial infections. Although both wild type OXA-66 and OXA-51 have low catalytic activity, they are ubiquitous in the Acinetobacter genomes. OXA-51 is also remarkably thermostable. In addition, newly emerging, single and double amino acid variants show increased activity against carbapenems, indicating that the OXA-51 subfamily is growing and gaining clinical significance. In this study, we used molecular dynamics simulations, X-ray crystallography, and thermal denaturation data to examine and compare the dynamics of OXA-66 wt and its gain-of-function variants: I129L (OXA-83), L167V (OXA-82), P130Q (OXA-109), P130A, and W222L (OXA-234). Our data indicate that OXA-66 wt also has a high melting temperature, and its remarkable stability is due to an extensive and rigid hydrophobic bridge formed by a number of residues around the active site and harbored by the three loops, P, Omega, and beta5-beta6. Compared to the WT enzyme, the mutants exhibit higher flexibility only in the loop regions, and are more stable than other robust carbapenemases, such as OXA-23 and OXA-24/40. All the mutants show increased rotational flexibility of residues I129 and W222, which allows carbapenems to bind. Overall, our data support the hypothesis that structural features in OXA-51 and OXA-66 promote evolution of multiple highly stable variants with increased clinical relevance in A. baumannii.

Structural and Dynamic Features of Acinetobacter baumannii OXA-66 beta-Lactamase Explain Its Stability and Evolution of Novel Variants.,Klamer ZL, June CM, Wawrzak Z, Taracila MA, Grey JA, Benn AMI, Russell CP, Bonomo RA, Powers RA, Leonard DA, Szarecka A J Mol Biol. 2024 May 8;436(12):168603. doi: 10.1016/j.jmb.2024.168603. PMID:38729259[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

  1. Klamer ZL, June CM, Wawrzak Z, Taracila MA, Grey JA, Benn AMI, Russell CP, Bonomo RA, Powers RA, Leonard DA, Szarecka A. Structural and Dynamic Features of Acinetobacter baumannii OXA-66 β-Lactamase Explain Its Stability and Evolution of Novel Variants. J Mol Biol. 2024 May 8;436(12):168603. PMID:38729259 doi:10.1016/j.jmb.2024.168603

8sq8, resolution 2.27Å

Drag the structure with the mouse to rotate

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA