DNA sequences of chromosomal integration site of S. flexneri phage SfI. Sequences obtained by PCR and sequencing of junction regions using a series of primers across the integration site. (A) attP in phage SfI. (B) attB in strain 036. (C) attL in strain 036_1a. (D) attR in 036_1a. Sequences in box are DNA regions between conserved genes; Underlined sequences are tRNA-thrW; Sequences in blue are att core sequence; Conserved genes are shaded and their transcription orientation is marked by an arrow.