FIG. 1.

Schematic linear maps of the plasmids used in this study. The linear plasmids and genes and sites contained within them are not drawn to scale. Genes and sites of importance are highlighted as follows: replicon type, blue; selectable marker genes, yellow; rep genes or gene fragments, red; antisense RNA gene, light red; lacZ reporter gene, purple. Zigzag lines, in-frame (translational) fusions between rep and lacZ. Premature stop codons (TAA) separate the rep and lac reading frames, with the latter containing translational start signals. Some promoters are indicated by arrows. Inactivated promoters are crossed over. Approximate positions of attenuators (Att) and rrnB terminators (rrnB-T) are shown. For more details, see the text.