FIG. 5.
Transcriptional fusions integrated into the lacI-lacZ region of the chromosome. The fusion point in strain GOB434 is 245 bp downstream from that in strain GOB435. P−1, P1, and P2 indicate promoters of the metY operon, and Ptet is the promoter for the tetracycline resistance gene of plasmid pBR322; T1 and T2 indicate the terminators between metY and p15a, and TrplS is the terminator of the trmD operon. Two different RNase III-processing sites are indicated, one (left-hand arrow) native to the region between metY and p15a and the other (right-hand arrow) present in the lacZ fusion vector used (22). For a description of the construction of the different fusions, see Materials and Methods.