Genomes of the P22-like phages of Salmonella. The genomes of four Salmonella temperate phages (P22, ε34, ST104 and ST64T) and two apparently intact Salmonella prophages (Scho1 and Para1; see text) are shown with the open reading frames indicated as colored rectangles. Similar rectangle colors indicate homology and these homologies are connected by yellow trapezoids between adjacent genomes; different open reading frame colors indicate apparent nonhomologies. The circular genome sequences are arbitrarily opened at the start of the small terminase gene. Above, the constant (among this type of phage) order of gene functions are indicated and think black lines between the genomes denote the apparent boundaries between these regions. Asterisks (*) mark genes where homology breaks clearly occur within genes (see text) and daggers (†) indicate the presences of tRNA genes (which read Asn GTT and Thr TGT codons in Scho1 and Asn GTT in Para1). The site of integration into the host genome is indicated at the attachment site (att) of each genome. Finally, the experimentally determined transcription pattern of phage P22 is indicated above the P22 genome (the gray arrowhead on the rightmost mRNA indicates that this transcript extends across the artificial break in the genome and continues at the other "end").