Figure 5.

Intramolecular recombination between attP and attB. (a) Restriction maps of pHS44 and the expected recombinant products. (b) Restriction analysis of parental and recombinant products after extraction of plasmid DNA from E. coli (lanes 1–3) or after recombination assays in vitro (lanes 4–7). BamHI and ScaI were used to analyze the plasmids from E. coli (lanes 1–3) and after in vitro recombination (lanes 7 and 8). In E. coli the recombinant product containing attL was barely visible (even though attR is abundant) because it does not contain an origin of replication and is lost. To detect the attR-containing circles obtained after recombination in vitro, BamHI alone was used (lanes 4 and 5), and this cut both the parental DNA and the attL-containing product. Molecular weight markers (M) are as in Fig. 2.