replication-associated protein; rep; ATP-dependent helicase rep; repP (Rep)

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Function

essential for the replication of viral ssDNA.
the closed circular ssDNA genome is first converted to a superhelical dsDNA.
rep &/or rep' binds a specific hairpin at the genome origin of replication.
introduces an endonucleolytic nick within the conserved sequence 5'-AGTATTAC-3' in the intergenic region of the genome, thus initiating rolling circle replication
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 replication
origin-specific DNA cleavage, & nucleotidyl transferase

Cofactors: Mg+2, Mn+2

ATP + H20 = ADP + HPO4- + H+ Structure:

there are 3 rolling circle replication (RCR) motifs.
RCR-2 is probably involved in metal coordination
RCR-3 is required for phosphodiester bond cleavage for initiation of RCR
belongs to the nanoviruses/circoviruses replication-associated protein family Compartment:
host nucleus