A physical map of the filamentous bacteriophage Cf genome

Twenty-three restriction endonucleases were used to cleave the genome of bacteriophage Cf. BamHI, EcoRI, HaeII, KpnI, PstI, SalI, SmaI and SstII each cut Cf DNA at one site, HindIII, PvuI, PvuII and XhoI cleaved at two sites, Bg/II cleaved at three sites, HincII cleaved at four sites, HinfI, BstNI, AluI, HpaII and HaeIII cleaved at 14, 19, 20, 24 and 26 sites, respectively, whereas HpaI and XbaI have no cleavage site on the Cf genome. HhaI and TaqI cleaved at more than 20 and more than 8 sites respectively. Based on the sizes of the fragments produced by digestion with these enzymes, Cf DNA was estimated to have 7.62 +/- 0.1 kilobase pairs. Using the EcoRI cleavage site as a reference point, nine restriction enzymes, BamHI, Bg/II, EcoRI, HindIII, KpnI, PstI, PvuII, SstII and XhoI were selected and a detailed physical map of the Cf genome was constructed.