FIG. 4.

Determination of the transcription start site of nasD by primer extension analysis. Total RNA was isolated from LAB2854 cells grown aerobically in TSS medium with 0.2% NH₄Cl (lane 1) or 0.2% KNO₃ (lane 2). RNA was also prepared from LAB2854 cells grown in 2× YT with 1% glucose, 20 mM phosphate buffer (pH 7.0), and 20 mM KNO₃ under aerobic (lane 3) or anaerobic (lane 4) conditions. The same oligonucleotide primer used for the primer extension analysis was used for sequencing by the dideoxy chain termination method (lanes G, A, T, and C).