FIG. 1.
Representation of the phage-inducible promoter fragment P15A10 (27). The five putative transcription start sites determined by O’Sullivan et al. (27) are represented by vertical arrows (numbered 1 to 5). A complete open reading frame (ORF2; nucleotides 219 to 650) located upstream of start sites 4 and 5 is indicated. This fragment showed constitutive activity which was induced three- to fourfold upon phage infection of the host. P15A10 was subcloned by PCR into five different regions, as indicated. Fragment 1–305 was generated by using the universal −40 primer (on pTRK391) and a primer complementary to nucleotides 281 to 306 on P15A10. Fragment 442–574 was amplified by using one primer consisting of nucleotides 442 to 457 and one primer complementary to nucleotides 559 to 574. Subclone 566–888 was generated by using a primer consisting of nucleotides 566 to 582 and the lacZ primer described in Materials and Methods (on pTRK391). Subclone 687–888 was amplified by using a primer consisting of nucleotides 687 to 705 (T→A and A→C mutations at nucleotides 691 and 692, respectively) and the lacZ primer. Subclone 566–732 utilized the nucleotide 566 primer and a primer complementary to nucleotides 714 to 732. Addition of a 5′ BamHI site to at least one primer of each pair facilitated subsequent cloning procedures.