FIG. 2.
(A) Portion of the orf29-orf30 intergenic region upstream from the mobC gene. The inverted repeats of hairpins A, B, and C are indicated by arrows. The 28-bp oriT is boxed, and the nic core site on the antisense strand is italicized. The nic site is indicated by an arrowhead. The initiation codon of the mobC gene is shown by a bent arrow. Nucleotides which have been substituted in pCM105 derivatives are in bold, and their positions are indicated. Numbering is from GenBank accession no. AF192329.1, but for the sake of simplicity in reading refers to the orf30 termination codon. (B) Mobilization of pACYCGm derivatives in E. coli recA:RP4::Δnic. Expression of the rlx gene was induced by 0.02% arabinose. The intergenic 250-bp orf29-orf30 fragment is shown with hairpins A, B, and C. Mutations are shown by arrowheads; when they were predicted to decrease the stability of the hairpins, the latter were deleted. Frequencies of transfer were the means of results of three independent mating experiments.