Figure 1

Test plasmid utilizing negative selection for quantitative measurement of plasmid loss. (a) Genetic map of a synthetic plasmid for studying isolated plasmid stability elements. Genetic modules are depicted as thick arrows, which include both the promoter and gene body. Vertical bars (|) represent unique restriction digestion sites, and a small circular symbol represents a transcriptional terminator. (b) Genetic mutants used to examine the mechanism of the R1 parCMR segregation system. Genetic elements are depicted as grayscale rectangles, with genes above or below the central line corresponding to the coding strand. The promoter within parC is indicated by a bent arrow. Smaller horizontal arrows indicate sequence repeats within parC that are important for ParR binding. An asterisk indicates a point mutant within parM. (c) Genetic mutants used to examine the function and mechanism of the Clostridium perfingens Alp16 parCMR segregation system. All Clostridial genes are depicted in shades of blue, with symbols as in (b).