Abstract
The genomes of Proteus mirabilis phages 5006M, kanamycin resistance transducing variant 5006 M HFT k and kanamycin-ampicillin resistance transducing variant 5006M HFT ak have been compared. Homo- and heteroduplex and partial denaturation mapping analyses were performed. The results confirm a sequential headful packaging mechanism, facilitate mapping of the ampicillin resistance marker, demonstrate a hairpin loop structure in both variants, reveal a common insertion site for 8 to 9 x 106 mol. wt. non-phage DNA in both variants and implicate a role for the non-inducible cryptic host strain prophage 5006M in the generation cycle of the variant phages.