@article{mbs:/content/journal/jgv/10.1099/0022-1317-81-9-2281, author = "Nawagitgul, Porntippa and Morozov, Igor and Bolin, Steven R. and Harms, Perry A. and Sorden, Steven D. and Paul, Prem S.", title = "Open reading frame 2 of porcine circovirus type 2 encodes a major capsid protein", journal= "Journal of General Virology", year = "2000", volume = "81", number = "9", pages = "2281-2287", doi = "https://doi.org/10.1099/0022-1317-81-9-2281", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-81-9-2281", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", abstract = "Porcine circovirus 2 (PCV2), a single-stranded DNA virus associated with post-weaning multisystemic wasting syndrome of swine, has two potential open reading frames, ORF1 and ORF2, greater than 600 nucleotides in length. ORF1 is predicted to encode a replication-associated protein (Rep) essential for replication of viral DNA, while ORF2 contains a conserved basic amino acid sequence at the N terminus resembling that of the major structural protein of chicken anaemia virus. Thus far, the structural protein(s) of PCV2 have not been identified. In this study, a viral structural protein of 30 kDa was identified in purified PCV2 particles. ORF2 of PCV2 was cloned into a baculovirus expression vector and the gene product was expressed in insect cells. The expressed ORF2 gene product had a molecular mass of 30 kDa, similar to that detected in purified virus particles. The recombinant ORF2 protein self-assembled to form capsid-like particles when viewed by electron microscopy. Antibodies against the ORF2 protein were detected in samples of sera obtained from pigs as early as 3 weeks after experimental infection with PCV2. These results show that the major structural protein of PCV2 is encoded by ORF2 and has a molecular mass of 30 kDa.", }