FIG. 4.

Restriction analysis of the L. paracasei Tn916 amplicon containing the coupling sequence. (A) Agarose gel electrophoresis of the amplicon obtained with primer pair V (Table 1). Lane 1, undigested control; lane 2, DraI digestion; lane 3, MspI digestion; lane 4, size marker (250 bp to 10 kb). (B and C) Theoretical restriction maps, obtained with NEB cutter version 2.0, of the circular form of Tn916 (GenBank accession no. U09422), indicating the positions of the DraI (B) and MspI (C) restriction sites. Arrows indicate primers used in PCR amplifications. Restriction sites mapping outside the amplified fragment are shown in parentheses. The DraI site interrupted by the coupling sequence is crossed. Fragment sizes (kb) are indicated between restriction sites.