from Koenraad Van Doorslaer, Vandana Sekhar, Jameela Khan, and Alison A. McBride writing in Small DNA Tumour Viruses:
Papillomaviruses persistently infect dividing epithelial cells. This cellular environment presents papillomaviruses with the challenge of having to replicate and retain their genome in proliferating cells. Papillomaviruses have evolved to maintain their genome as an extra-chromosomal element. The viral E2 protein binds to the viral genome and tethers it to the host chromosomes. This chapter will review some of the recent work showing how different papillomaviruses have evolved variations on this theme. Where appropriate, parallels will be drawn with other persistent, double-stranded DNA viruses.
Further reading: Small DNA Tumour Viruses Related publications