FIGURE 1.

The noncoding intergenic M13 origin of replication, which is found in the plasmid LITMUS 28 from 1043 to 1545 bp (between the HpaI and HincII cut sites). Highlighted are the ribosome binding site at 1043–1056 bp, the Pribnow box (−10) and −35 hexamer, shown as boxes ∼8 bp and 35 bp from the gpII mRNA start site at 1077 bp, the start site for replication of complementary (minus) strand DNA synthesis ((−) ori RNA) at 1265 bp and the viral (plus) strand initiation site ((+) ori DNA) at 1291 bp, which are indicated by arrows, and the gpII nick site at 1266 bp. The sequence between 925 and 1042 bp belongs to the ampicillin resistance gene. The 471-bp fragment used in this study was obtained by using the restriction enzymes AhdI/BanII to digest the plasmid at 931 and 1402 bp.