[The role of structural elements of ColE1-related plasmids in replication control]

Effect of deletions downstream from the replication origin on copy number of ColE1 related (pBR322 derived) plasmids has been studied. Along with main control elements (RNAI of defined secondary structure, the repressor protein, effectiveness of promoter upstream of gene of RNA primer) replication is influenced by transcription level propagated into the replicon region from promoters even in distal parts of plasmid. Structure of the region adjacent to the ori is important for startpoint recognition specificity, so that deletion of this region reduces the effectiveness of replication.