Rolling circle replication
Rolling circle replication is a process which a circular DNA or RNA molecule is replicated in one direction. This particular process occurs in plasmid and virus’s genome.
Rolling Circle Replication Mechanism in DNA
The process in DNA is initiated by initiator protein which nicks at the site called the double stranded origin on one strand of the double-strand. The initiator protein remains on the 5’ phosphate nick strand, and the 3’ hydroxyl end of the nick strand is elongated by DNA polymerase III. The unnicked strand acts as the template strand for replication and the 5’ phosphate nick strand is displace by helicase. Eventually, the nick strand is completely displaced by newly synthesis strand and will remove itself from the original circular DNA by the same initiator protein nicking at the terminating sequence on the nick strand. The nick strand then form a new single stranded circular DNA molecule. RNA polymerase and DNA polymerase III then use the single strand as template to form new double stranded circular DNA molecule.
- ↑ Ruiz-Masó J, MachóN C, Bordanaba-Ruiseco L, Espinosa M, Coll M, Del Solar G. Plasmid rolling-circle replication. microbiolspectrum. 2015;3;10.1128