5KMT

CTX-M9 mutant L48A

Summary for 5KMT

• Entry DOI: 10.2210/pdb5kmt/pdb
• Related: 5KMU
• Descriptor: Beta-lactamase, PHOSPHATE ION, POTASSIUM ION, ... (4 entities in total)
• Functional Keywords: beta lactamase, esbl, hydrolase
• Biological source: Escherichia coli
• Total number of polymer chains: 2
• Total formula weight: 62212.40

Authors

Latallo, M.J.,Faham, S.,Kasson, P.M. (deposition date: 2016-06-27, release date: 2017-08-02, Last modification date: 2024-03-06)

Primary citation

Latallo, M.J.,Cortina, G.A.,Faham, S.,Nakamoto, R.K.,Kasson, P.M.
Predicting allosteric mutants that increase activity of a major antibiotic resistance enzyme.
Chem Sci, 8:6484-6492, 2017

PubMed Abstract: The CTX-M family of beta lactamases mediate broad-spectrum antibiotic resistance and are present in the majority of drug-resistant Gram-negative bacterial infections worldwide. Allosteric mutations that increase catalytic rates of these drug resistance enzymes have been identified in clinical isolates but are challenging to predict prospectively. We have used molecular dynamics simulations to predict allosteric mutants increasing CTX-M9 drug resistance, experimentally testing top mutants using multiple antibiotics. Purified enzymes show an increase in catalytic rate and efficiency, while mutant crystal structures show no detectable changes from wild-type CTX-M9. We hypothesize that increased drug resistance results from changes in the conformational ensemble of an acyl intermediate in hydrolysis. Machine-learning analyses on the three top mutants identify changes to the binding-pocket conformational ensemble by which these allosteric mutations transmit their effect. These findings show how molecular simulation can predict how allosteric mutations alter active-site conformational equilibria to increase catalytic rates and thus resistance against common clinically used antibiotics.

PubMed: 28989673
DOI: 10.1039/c7sc02676e

Experimental method

X-RAY DIFFRACTION (1.7 Å)