Structural highlights
Function
REP_PCV2 Essential for the replication of viral ssDNA. The closed circular ssDNA genome is first converted to a superhelical dsDNA. Rep and/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, 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, and nucleotidyl transferase.[1] [2]
References
- ↑ Cheung AK. The essential and nonessential transcription units for viral protein synthesis and DNA replication of porcine circovirus type 2. Virology. 2003 Sep 1;313(2):452-9. PMID:12954212 doi:10.1016/s0042-6822(03)00373-8
- ↑ Cheung AK. Specific functions of the Rep and Rep׳ proteins of porcine circovirus during copy-release and rolling-circle DNA replication. Virology. 2015 Jul;481:43-50. PMID:25768890 doi:10.1016/j.virol.2015.01.004
