FIG. 1.
Construction of the lacZ-cat-Plac and lacZ-aph-Plac reporter cassettes. The constructions were started with pRS551 (top left) and the amplification of FRT sites (bottom left). The large shaded arrows indicate the path of construction, which is described in detail in the text. T marks the weak transcription terminator in trp. Restriction sites are indicated with one or two letters: B, BamHI; Ec, EcoRI; E, Ecl136; Hc, HincII; H, HindIII; N, NotI; Sa, SacI; Sm, SmaI; Sb, SnaBI; and St, StuI. The short solid arrows mark FRT sites. Intact genes and their directions of transcription are shown as long solid arrows on the DNA. Untranscribed gene fragments are shown as solid bars. Vertical dotted reference lines connect points with the same DNA sequence. All named plasmids are further described in Table 1.