FIG. 2.

Alignment of sequences at −10 and downstream of lmr promoters of 168, 1A221, and 18 lincomycin-resistant mutants. PCR products were prepared from 168, 1A221, and mutant chromosomal DNA with the primer set PR7 (5′-TGCTGCCGACGTTAACAATC-3′) and PR8 (5′-AGCAGTCCTGAAACAGGAAC-3′) to sequence promoter and lmrA regions. Uppercase letters, replaced nucleotides in 1A221 and mutants; -, deleted nucleotides. Each sequence was analyzed at least three times, and the results were identical. Consensus positions of replaced nucleotides that confer lincomycin resistance are boxed. Arrows, transcriptional start points (+1) in 1A221 and six mutants (LR 26, 31, 32, 44, 45, and 52) determined by primer extension. The MICs of lincomycin for the wild type and the resistant mutants were determined by the agar dilution method proposed by the National Committee for Clinical Laboratory Standards. Dots, different nucleotides between 168 and 1A221 in the sequenced region.