FIG. 7.

Determination of the start codon of the tetQ gene. The Pq regions in all five of the constructs start from −333 bp upstream of tetQ, but each ends at a different position. The Pq region in pTUG13-in3 ends at the GTG putative start codon of tetQ. In pTUG13-in2, the ATG start codon was fused to the uidA gene. In both pTUG13-in1 and pYP48, the Pq region ends at the sixth amino acid of TetQ and was fused to the uidA gene. The Pq region in pYP48 is the same as that in pTUG13-in1 except that two stop codons, which are indicated by a circle, were put between GTG and ATG, their exact positions are shown in Fig. 8A. Tc, TET.