| Literature DB >> 28994407 |
Bjarte Aarmo Lund1, Ane Molden Thomassen1, Trine Josefine Olsen Carlsen1, Hanna Kirsti S Leiros1.
Abstract
The first crystal structures of the class D β-lactamases OXA-181 and OXA-245 were determined to 2.05 and 2.20 Å resolution, respectively; in addition, the structure of a new crystal form of OXA-163 was resolved to 2.07 Å resolution. All of these enzymes are OXA-48-like and have been isolated from different clinical Klebsiella pneumoniae strains and also from other human pathogens such as Pseudomonas aeruginosa and Escherichia coli. Here, enzyme kinetics and thermostability studies are presented, and the new crystal structures are used to explain the observed variations. OXA-245 had the highest melting point (Tm = 55.8°C), as determined by differential scanning calorimetry, compared with OXA-163 (Tm = 49.4°C) and OXA-181 (Tm = 52.6°C). The differences could be explained by the loss of two salt bridges in OXA-163, and an overall decrease in the polarity of the surface of OXA-181 compared with OXA-245.Entities:
Keywords: OXA-163; OXA-181; OXA-245; X-ray crystal structure; antibiotic resistance; carbapenemase; enzyme kinetics; thermostability; β-lactamase
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Year: 2017 PMID： 28994407 PMCID： PMC5633926 DOI： 10.1107/S2053230X17013838
Source DB: PubMed Journal: Acta Crystallogr F Struct Biol Commun ISSN： 2053-230X Impact factor: 1.056