3QNC

Crystal Structure of a Rationally Designed OXA-10 Variant Showing Carbapenemase Activity, OXA-10loop48

Summary for 3QNC

• Entry DOI: 10.2210/pdb3qnc/pdb
• Related: 3QNB
• Descriptor: Oxacillinase, SULFATE ION, 1,2-ETHANEDIOL, ... (5 entities in total)
• Functional Keywords: antibiotic resistance, hydrolysis of amide bond of beta-lactam compounds, hydrolase
• Biological source: Escherichia coli; More
• Total number of polymer chains: 2
• Total formula weight: 56541.95

Authors

De Luca, F.,Benvenuti, M.,Carboni, F.,Pozzi, C.,Rossolini, G.M.,Mangani, S.,Docquier, J.D. (deposition date: 2011-02-08, release date: 2011-11-02, Last modification date: 2023-12-06)

Primary citation

De Luca, F.,Benvenuti, M.,Carboni, F.,Pozzi, C.,Rossolini, G.M.,Mangani, S.,Docquier, J.D.
Evolution to carbapenem-hydrolyzing activity in noncarbapenemase class D {beta}-lactamase OXA-10 by rational protein design.
Proc.Natl.Acad.Sci.USA, 108:18424-18429, 2011

PubMed Abstract: Class D β-lactamases with carbapenemase activity are emerging as carbapenem-resistance determinants in gram-negative bacterial pathogens, mostly Acinetobacter baumannii and Klebsiella pneumoniae. Carbapenemase activity is an unusual feature among class D β-lactamases, and the structural elements responsible for this activity remain unclear. Based on structural and molecular dynamics data, we previously hypothesized a potential role of the residues located in the short-loop connecting strands β5 and β6 (the β5-β6 loop) in conferring the carbapenemase activity of the OXA-48 enzyme. In this work, the narrow-spectrum OXA-10 class D β-lactamase, which is unable to hydrolyze carbapenems, was used as a model to investigate the possibility of evolving carbapenemase activity by replacement of the β5-β6 loop with those present in three different lineages of class D carbapenemases (OXA-23, OXA-24, and OXA-48). Biological assays and kinetic measurements showed that all three OXA-10-derived hybrids acquired significant carbapenemase activity. Structural analysis of the OXA-10loop24 and OXA-10loop48 hybrids revealed no significant changes in the molecular fold of the enzyme, except for the orientation of the substituted β5-β6 loops, which was reminiscent of that found in their parental enzymes. These results demonstrate the crucial role of the β5-β6 loop in the carbapenemase activity of class D β-lactamases, and provide previously unexplored insights into the mechanism by which these enzymes can evolve carbapenemase activity.

PubMed: 22042844
DOI: 10.1073/pnas.1110530108

Experimental method

X-RAY DIFFRACTION (1.6 Å)