Northern blot analysis to detect ompG-specific transcripts. Total RNA (3 μg) obtained from DME553 (cog+; lanes 1 and 7), RAM123 (cog-192; lanes 2 and 8), RAM123 recA::Kmr (lane 3), RAM123 recA::Kmr/pBR322 (lane 4), RAM123 recA::Kmr/pBR322-pspFAB (lane 5), and RAM123 recA::Kmr/pBR322-pspA (lane 6) was probed with an ompG-specific probe. Molecular sizes of the two ompG-specific mRNA species are 1.4 and 2.0 kb.