The nucleotide sequence surrounding the replication origin of the cop3 mutant of the bacterio-cinogenic plasmid Clo DF13

The nucleotide sequence from about 100 base-pairs downstream to about 600 base pairs upstream the CloDF13 replication origin has been determined. A comparison of this sequence with the corresponding ColE1 origin sequence reveals that: The sequence at the origin of replication is conserved. There are large differences in the nucleotide sequence downstream the replication origin, whereas there is a large homology in the region of about 410 base-pairs upstream the replication origin. This conserved region might code for a largely homologous basic, arginine rich polypeptide of about 45 amino-acids, for both ColE1 and CloDF13. Although there are large differences in the primary structure of the region coding for the 100 nucleotide RNA, the secondary structure of this region seems to be conserved.