FIG. 6.

Effects of NMB1965 genetic inactivation on growth and growth phase-dependent expression of NMB1965. (A) Growth curves of H44/76 and H44/76ΩNMB1965 (permease defective) in GC-rich broth. The lag phase is omitted. (B) Slot blot analysis of NMB1965-specific transcripts. Top, total RNAs were extracted from H44/76 and H44/76ΩgdhR grown in GC-rich broth to middle (OD₅₅₀ of 0.4) or to late logarithmic phase (OD₅₅₀ of 0.8). The RNAs (0.01, 0.1, and 1 μg) were fixed onto Hybond-N+ nylon membranes and hybridized to the ³²P-labeled NMB1965-specific probe used in Northern blot experiments (Fig. 2B). Bottom, densitometry analysis of the slot blot. The transcript level in H44/76 grown to an OD₅₅₀ of 0.8 is arbitrarily assumed to be equal to 100%. Values represent means from three independent experiments, each with triplicate samples. Bars indicate standard deviations. (C) Strains H44/76, H44/76ΩNMB1963 (periplasmic substrate-binding protein defective), and H44/76ΩNMB1965 were streaked on GC medium, MCDA-1, or MCDA-2 agar plates.