Genomic characterization of Erethizon dorsatum papillomavirus 2, a new papillomavirus species marked by its exceptional genome size.

We report here the complete sequence and genome organization of a new papillomavirus, Erethizon dorsatum papillomavirus 2 (EdPV2), which was isolated from cutaneous lesions observed on the muzzle of a North American porcupine. The complete genome is 8809 nucleotides long and encodes five early (E6-E7-E1-E2-E4) and two late proteins (L2-L1). In addition to the upstream regulatory region, the EdPV2 genome contains an exceptionally large secondary non-coding region with no apparent functional relevance. EdPV2 is strongly divergent from the previously described porcupine papillomavirus EdPV1 and phylogenetic analysis shows EdPV2 clustering near members of the genus Pipapillomavirus, a group of rodent papillomaviruses. Pairwise sequence comparison based on the L1 open reading frame identifies Rattus norvegicus papillomavirus 1 as the closest related virus (59.97 % similarity). Based on its low sequence similarity to other known papillomaviruses, EdPV2 is thought to represent a new genus in the family Papillomaviridae.