Primary structure of OXA-3 and phylogeny of oxacillin-hydrolyzing class D beta-lactamases
Sanschagrin, F.; Couture, F.; Levesque, R.C.
Antimicrobial Agents and ChemoTherapy 39(4): 887-893
1995
ISSN/ISBN: 0066-4804 PMID: 7785990 Document Number: 440665
We determined the nucleotide sequence of the bla-OXA-3(pMG25) gene from Pseudomonas aeruginosa. The bla structural gene encoded a protein of 275 amino acids representing one monomer of 31,879 Da for the OXA-3 enzyme. Comparisons between the OXA-3 nucleotide and amino acid sequences and those of class A, B, C, and D beta-lactamases were performed. An alignment of the eight known class D beta-lactamases including OXA-3 demonstrated the presence of conserved amino acids. In addition, conserved motifs composed of identical amino acids typical of penicillin-recognizing proteins and specific class D motifs were identified. These conserved motifs were considered for possible roles in the structure and function of oxacillinases. On the basis of the alignment and identity scores, a dendrogram was constructed. The phylogenetic data obtained revealed five groups of class D beta-lactamases with large evolutionary distances between each group.