FIG 3.

Amino acid sequence alignment of the DHA β-lactamase family (DHA-1, GenBank accession no. Y16410; DHA-6, HQ322612; DHA-7, HQ456945) with AmpC from Escherichia coli. Asterisks indicate strictly conserved amino acids, two dots indicate residues that are very similar, and one dot indicates residues that are more or less similar. Ala226Thr and Phe322Ser mutation positions are 0. The three classical conserved motifs are shaded in gray, the omega loop is indicated by a solid black line, and the H2 and H10 helices are represented by dashed lines. The alignment was created with the CLUSTAL W program of the EMBL-EBL.