FEATURES

FAMILY

nanoviridea/circoviridae replication-associated protein family

DESCRIPTION

Also known as MREP_SCSVF, DNA-R, C8. Essential for the replication of all genomic viral ssDNA (trans-replication). The closed circular ssDNA genome is first converted to a superhelical dsDNA. Rep binds a specific hairpin at the genome origin of replication. Introduces an endonucleolytic nick within the conserved sequence 5'-A[GT]TATTAC-3' in the intergenic region of the genome, thereby initiating the rolling circle replication (RCR). Following cleavage, binds covalently to the 5'-phosphate of DNA as a tyrosyl ester. The cleavage gives rise to a free 3'-OH that serves as a primer for the cellular DNA polymerase. The polymerase synthesizes the (+) strand DNA by rolling circle mechanism. After one round of replication, a Rep-catalyzed nucleotidyl transfer reaction releases a circular single-stranded virus genome, thereby terminating the replication. Displays origin-specific DNA cleavage, nucleotidyl transferase, ATPase and helicase activities (By similarity). Homooligomer (Potential). Rep binds to repeated DNA motifs (iterons) (By similarity).

EXTERNAL LINKS

DNA-R

Master replication protein

DNA-R

Molecular Synopsis