Figure 4.

Influence of the relative position of the promoter and the dre site in pgi gene. (A) Binding site of NagR_Bt and promoter in the upstream region of pgi gene. The putative−35 and−10 positions (predicted by Neural Network Promoter Prediction, http://www.fruitfly.org/seq_tools/promoter.html, score 0.94) are shaded. The corresponding predicted +1 is indicated by a bent arrow and the dre site is boxed. The pgi promoter region (underlined) was amplified with primers (Ppgi-F and Ppgi-R). The fragment with the dre site before the promoter (i.e., native configuration) was amplified with primers (Pdre+Ppgi-F and Ppgi-R) and the fragment with dre site after the promoter with primers (Ppgi-F and Ppgi+dre-R). (B) Schematic diagram of the change in the relative position with promoter and dre site. (C) qRT-PCR was used to examine the expression of bgaB in three plasmids (pdre^pgi+Ppgi, pPpgi+dre^pgi, and pPpgi) in wild-type strain Bti75. (D) β-galactosidase activity assay of three plasmids (pdre^pgi+Ppgi, pPpgi+dre^pgi, and pPpgi) in wild-type strain Bti75. Significance was calculated by two-sample t-test (*p < 0.05, **p < 0.01, and ***p < 0.001).