Lecture 5 - Mobile genetic elements

Question 1

oriV

Answer 1

Origin of replication. A plasmid must contain oriV in order to replicate itself.

Question 2

Replication of circular parasites

Answer 2

Rolling circle replication: replication of only one strand from a double-stranded circular DNA.

Question 3

Rolling circle version 1

Answer 3

After DNA is nicked, the circle rolls, and leads to either cleavage of a unit length strand which circularizes and then becomes a duplex or a multimer strand which forms a duplex and then is encircled.

Question 4

Rolling circle version 2

Answer 4

The DNA is nicked by a protein. Rolling circle displaces the minus strand and the protein then nicks the origin - now formed a double-stranded and a single- stranded plasmid. More organised and controlled than version 1.