Fig. 4.

(A) The 3′ RACE assay on transcripts generated from in vitro transcription of WT and RIT^o2 mutant. In vitro transcription reactions were performed in the presence of different concentrations of NusA as indicated. (B) Northern analysis of the gal full-length transcripts generated in the RIT^o1–4 series mutants. The mM1* band is about 100 nucleotides smaller than the mM1 band and was generated in all of the RIT^o1–4 series mutants due to the impaired terminator hairpin structure. Note that as more base pairs from the foot of the stem of the terminator hairpin are removed, greater amounts of mM2 are generated. The mM2 RNA bands were quantified by scanning; the relative expression levels of mM2 for WT, RIT⁰1, RIT⁰2, RIT⁰3, and RIT⁰4 strains, were 0, 1.0, 6.4, 9.8, and 25.1, respectively. (C) The 3′ RACE assay on transcripts generated in the RIT^o1–4 series mutants in (B). Numbers indicate the 3′ end position of the transcripts generated in vivo. (D) Northern analysis of the full-length transcripts generated from the WT and the RIT^o2 mutant in GW20Δgal (temperature-sensitive RNase E mutant) cells in which the entire gal operon is deleted from the chromosome. Analysis was performed on cells grown at the permissive temperature (30 °C) and at the nonpermissive temperature (44 °C).