FIG. 1.

Genetic map and ORFs deduced from the complete plasmid sequence of pHTβ plasmid. Boxes indicate ORFs identified on the pHT plasmid. The locations of the Tn917-lac insertions of pHTβ (vertical bar with circular head) are shown on the map. Each head color shows the transfer frequency of the derivatives (white; transfer frequency the same as parent plasmid, black; transfer frequency less than one-fifth of the frequency of the parent plasmid or no transfer by broth mating). The number on the insert (1 through 29) indicates the representative plasmids of the derivatives, which are also shown in Fig. 2 and Table 3. Horizontal bars designated as Tra regions I, II, and III on the map indicate the transfer-related regions. DR and IR indicate the direct repeat sequences and inverted repeat sequences. The asterisks under the map indicate the sequence resembling the consensus oriT sites of IncP, IncQ, or oriT of the F plasmid. Black horizontal bars designated a through q under the map show the cloned DNA segments used for the identification of the oriT region of the pHT plasmid. The clones are as follows: a, pAM401::ORF1; b, pAM401::IR4; c, pAM401::IR3; d, pAM401::119/113; e, pAM401::ORF19/21; f, pAM401::119/96; g, pAM401::IR5-1; h, pAM401::ORF39/40; i, pAM401::IR1; j, pAM401::DR1; k, pAM401::ORF51/52; l, pAM401::ORF53/56; m, pAM401::traA; n, pAM401::IR2; o, pAM401::ORF58; p, pAM401::rep5′; and q, pAM401::ORF60/61.