4WMC: Oxa-48 Covalent Complex With Avibactam Inhibitor

The Class D (or OXA-type) beta-lactamases have expanded to be the most diverse group of serine beta-lactamases with a highly heterogeneous beta-lactam hydrolysis profile and are typically resistant to marketed beta-lactamase inhibitors. Class D enzymes are increasingly found in multidrug resistant (MDR) Acinetobacter baumannii, Pseudomonas aeruginosa, and various species of the Enterobacteriaceae and are posing a serious threat to the clinical utility of beta-lactams including the carbapenems, which are typically reserved as the drugs of last resort. Avibactam, a novel non-beta-lactam beta-lactamase inhibitor, not only inhibits all class A and class C beta-lactamases but also has the promise of inhibition of certain OXA enzymes, thus extending the antibacterial activity of the beta-lactam used in combination to the organisms that produce these enzymes. X-ray structures of OXA-24 and OXA-48 in complex with avibactam revealed the binding mode of this inhibitor in this diverse class of enzymes and provides a rationale for selective inhibition of OXA-48 members. Additionally, various subunits of the OXA-48 structure in the asymmetric unit provide snapshots of different states of the inhibited enzyme. Overall, these data provide the first structural evidence of the exceptionally slow reversibility observed with avibactam in class D beta-lactamases. Mechanisms for acylation and deacylation of avibactam by class D enzymes are proposed, and the likely extent of inhibition of class D beta-lactamases by avibactam is discussed.
PDB ID: 4WMCDownload
MMDB ID: 125310
PDB Deposition Date: 2014/10/8
Updated in MMDB: 2014/12
Experimental Method:
x-ray diffraction
Resolution: 2.3  Å
Source Organism:
Similar Structures:
Biological Unit for 4WMC: dimeric; determined by author and by software (PISA)
Molecular Components in 4WMC
Label Count Molecule
Proteins (2 molecules)
Molecule annotation
Chemicals (3 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB