Figure 7

Transcription of the pnp gene from the pnp promoter is not affected by Hfq. Total RNA was extracted from strains N3433 (hfq⁺), IBPC929 (hfq 1), IBPC633 (rnc^-) and IBPC927 (rnc^- hfq^-) and the 5'-extremities of the pnp transcripts (in equal amounts of RNA) were mapped by primer extension using a 5'-labeled oligonucleotide complementary to the pnp mRNA region 160 nucleotides downstream of the RNase III processing site. The right lane shows the 5'-labeled RNA size markers separated on the same gel. M2 and t bands corresponding to arrest of reverse transcription at an RNase E processing site and a stable hairpin within the rpsO-pnp bicistronic transcript from the rpsO promoter, P2 and RIII- transcripts from the pnp promoter unprocessed and processed by RNase III, respectively.