FIG. 4.

Sequence comparison between the IMP-1 (28) and IMP-2 proteins and additional comparison with Bc-II of B. cereus 569/H (15). Identical residues are indicated by an asterisk; conserved amino acid substitutions are indicated by a colon. Identity and similarity symbols reported below the Bc-II sequence refer to the comparison among the three sequences, while those reported below the IMP-2 sequence refer to the comparison between IMP-1 and IMP-2. The highly conserved residues known to be involved in the binding of zinc ions in the B. cereus and B. fragilis metallo-β-lactamases (7, 8, 10) are boxed. Secondary structure elements of Bc-II (8) are also indicated above the sequence.