Journal of Molecular Evolution

, Volume 59, Issue 1, pp 133–141

Independent Origins of Subgroup Bl+B2 and Subgroup B3Metallo-β-Lactamases


    • Biology DepartmentUniversity of Rochester
  • Stephen J. Salipante
    • Biology DepartmentUniversity of Rochester
  • Miriam Barlow
    • Biology DepartmentUniversity of Rochester

DOI: 10.1007/s00239-003-2572-9

Cite this article as:
Hall, B.G., Salipante, S.J. & Barlow, M. J Mol Evol (2004) 59: 133. doi:10.1007/s00239-003-2572-9


The metallo-β-lactamases constitute Class B in the Ambler classification of β-lactamases and are divided into three subclasses: Bl, B2, and B3. Bayesian phylogenies of the Subclass B1+B2 and Subclass B3 metallo-β-lactamases and their homologs show that the β-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-β-lactamases should be divided into two distinct classes.


Metallo-β-lactamasesSubgroup B1+B2Subgroup B3Ambler classification

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© Springer-Verlag 2004