FIG. 1.

Organization of plasmid pC223 (4,608 bp). The map is oriented with the nick site of the double-stranded replication origin (dso) at the +1 position. Novel sequence data obtained in the present study are indicated by the solid bar on the map; amendments to previously available data are concentrated in the shaded region. The principal reading frames are indicated by the open arrows. sso indicates the site and orientation of the single-stranded (−) replication origin. The nick site within the origin of transfer determined in the present study is given as nic. The layout of pC221 is similar, although the two plasmids have considerably reduced sequence identity in the region shown by the dashed line.