Symmetric rolling circle replication

Related to: Avsunviroids and Hepatitis delta

Location: Host cell nucleus (Human), Chloroplast (plant).

Replication events: Avsunviroids and hepatitis delta replicate their genome through rolling circle by a host RNA polymerase that generate linear multimers from circular RNA template. These multimers are subsequently cleaved to unit-length RNAs by self-cleavage (these RNAs contain ribozymes, meaning that they possess enzymatic activity in the absence of proteins). New linear antigenomes are further circularized. The circular antigenome replicates by the same rolling circle mechanism to produce new genomes. This replication is called “symmetric replication” since both plus and minus strands are produced the same way