Figure 2.

Sequence logos for group 1 (A), group 2 (B) and group 3 (C) residue positions. (A) For group 1 positions, the wild-type residue dominates among sequences from populations selected at both high and low imipenem concentrations. (B) For group 2 positions, wild type sequences predominate in selections at high imipenem concentrations but other amino acid types are found at low imipenem concentrations. (C) For group 3 positions, the wild-type residue does not predominate even in selections at high impenem concentrations.