Figure 2.

(A) Northern blot hybridization of a riboprobe specific for nblA to RNA from wild type (WT) grown in complete medium (+) and WT and the nblR mutant (R) grown in medium devoid of sulfur (−S) or nitrogen (−N) for 24 h. Molecular weight markers (MW) are in kbp. (B) Northern blot hybridization of a probe specific for rhdA to RNA from WT and the nblR mutant grown in complete medium (+) and medium devoid of sulfur (−S) for 4 h. Hybridization to rRNA served as loading controls. (C) GUS activity in WT and the nblR mutant harboring a plasmid with the chimeric nblA (promoter)-GUS reporter gene. GUS activity was measured in cells grown in complete medium (+) or after 24 h of starvation for sulfur (−S) or nitrogen (−N). (D) GUS activity determined for WT and the nblR mutant during growth on complete medium (note the expanded scale on the y axis).