Genomic structure of the cottontail rabbit (Shope) papillomavirus.

The nucleotide sequence of the cottontail rabbit papillomavirus (CRPV or Shope papillomavirus) genome has been determined. The overall organization of the genome is similar to that of the other three papillomaviruses already sequenced. The amino acid sequences of the putative viral proteins were compared to the available protein data banks. Of particular interest is the homology found between the COOH terminus of the E2 putative protein of the different papillomaviruses and the viral or cellular mos oncogene product. This analysis also reveals a specific feature of the rabbit virus that may be related to its natural oncogenic potential. One of its open reading frames (E6) shows significant homologies with the beta subunit of a family of ATP synthases from mitochondria, chloroplasts, and bacteria, including the conservation of amino acids residues involved in nucleotide binding. The viral noncoding region includes a highly A+T-rich segment and shows a complex array of repetitions and inverted repeats that may act as control elements for gene expression and genome replication.