FIG 1.

Mutations within the LexA binding site directly upstream of the qnrB1 gene. The sequences flanking the 5′ end of the qnrB1 ORF from the three detected qnrB1 subvariants (qnrB1a, qnrB1d, and qnrB1i) were aligned with the analogous region from the prototype qnrB1 gene (GenBank accession number DQ351241). The nucleotide position numbers are based on the prototype qnrB1 gene sequence and denote the distance from the first nucleotide of the translation initiation codon (labeled +1). The sequences enclosed in the black box indicate the LexA binding motif. The vertical arrows indicate the point mutation sites characteristic of the particular qnrB1 gene variants (a, qnrB1a [qnrB6a]; d, qnrB1d; i, qnrB1i).