FIG. 4.

Primer extension analysis of flagellin gene transcription. RNA was prepared from the wild-type strain BB22 after growth in HI broth (B) or on HI plates (P). The amount of RNA in each lane was as follows: 1, 2 μg (B); 2, 2 μg (P); 3, 2 μg (B); 4, 5 μg (P); 5, minus RNA; 6, minus RNA; and 7, 2 μg (B). Lanes g, a, t, and c correspond to the dideoxy nucleotide used in the sequencing reactions. Sequence and primer extension products were generated with flaA-, flaB-, or flaD-specific primers. The primers were flaA (5′-GCTGTGCGGTCATCGCAGAAACG-3′), flaB (5′-GTGTTTAATTCACTGCCATG-3′), and flaD (5′-CGGTCATCGCTGATACGTTAGTG-3′).