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Published on: May 2, 2018
Independent origins of subgroup Bl + B2 and subgroup B3 metallo-beta-lactamases
Barry G Hall1, Stephen J Salipante, Miriam Barlow
1Biology Department, University of Rochester, Rochester, NY 14627, USA. drbh@mail.rochester.edu
Abstract:
The metallo-beta-lactamases constitute Class B in the Ambler classification of beta-lactamases and are divided into three subclasses: Bl, B2, and B3. Bayesian phylogenies of the Subclass B1 + B2 and Subclass B3 metallo-beta-lactamases and their homologs show that the beta-lactam-hydrolyzing function evolved independently within each group. In Subclass B1+B2 that function evolved about 1 billion years ago, and in Subclass B3 it evolved before the divergence of the Gram-positive and Gram-negative eubacteria, about 2 billion years ago. These results lend additional support to the proposal that the metallo-beta-lactamases should be divided into two distinct classes.
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