Figure 17.3.4.

lacZ reporter plasmid. pRB1840, pJK103, and pSH18-34 are all derivatives of LR1Δ1 (West et al., 1984) containing eight, two, or one operator for LexA (LexA_op) binding inserted into the unique XhoI site located in the minimal GAL1 promoter (GAL1_pro; 0.28 on map). The plasmid contains the URA3 selectable marker, the 2-μm origin to allow propagation in yeast, the ampicillin resistance gene (Ap^r), and the pBR322 origin (ori) to allow propagation in E. coli. Numbers indicate relative map positions. In the recently developed derivatives, the ampicillin resistance gene has been replaced with the chloramphenicol or kanamycin resistance genes (see Table 17.3.1 for details).