ColE1 plasmid belongs to the family of bacteriocins.
It is a relaxed plasmid, meaning it has multiple copy numbers (many copies per cell).
The plasmid is 6646 base pairs long, circular, and closed.
ColE1 plasmid produces colicin E1.
It is a non-conjugative plasmid, as it lacks the genes required for conjugation and cannot be transferred from one bacterial cell to another through the pilus.
In the ColE1 plasmid, the replication process is controlled by an antisense RNA molecule.
Structure of ColE1 Plasmid
It is a small, closed circular plasmid.
The molecular weight of the ColE1 plasmid is 4.2×10^6 Da, and it is 6646 base pairs in length.
It lacks the mob gene (mobility genes) and the bom sequence (basis of mobility), preventing it from independently completing transmission.
It contains the colicin E1 gene, which produces bacteriocin, and also codes for immunity against bacteriocin with the imm gene.
Origin of replication
The origin of replication of the ColE1 plasmid is located in a region about 1 kb in size.
It is situated 555 base pairs downstream from the RNA II start point.
ColE1 plasmids replicate via the theta-type mechanism.
The replication process is unidirectional.
Restriction sites
The restriction enzyme EcoR1 cleaves the ColE1 plasmid at a specific site.
EcoR1 cuts the DNA strands at the 5' GAATTC 3' sequence.
Advantages of ColE1 Plasmid
ColE1 serves as a basis for many artificial vectors used in the cloning process.
ColE1 plasmids are resistant to a wide range of antibiotics, making them valuable tools in genetic engineering.
For industrial purposes, colicin genes are often replaced by antibiotic resistance genes.
The resistance genes in host bacteria enable them to evade the effects of bacteriocin.
The transmembrane protein Colicin E1 causes lethal membrane depolarization in bacteria.
