Sequence analysis of a porcine enterovirus serotype 1 isolate: relationships with other picornaviruses.

The majority of the genomic sequence of a porcine enterovirus serotype 1 (PEV-1) isolate was determined. The genome was found to contain a large open reading frame which encoded a leader protein prior to the capsid protein region. This showed no sequence identity to other picornavirus leader regions and the sequence data suggested that it does not possess proteolytic activity. The 2A protease was small and showed considerable sequence identity to the aphthoviruses and to equine rhinovirus serotype 2. The 2A/2B junction possessed the typical cleavage site (NPG/P) exhibited by these viruses. The other proteins shared less than 40% sequence identity with equivalent proteins from other picornavirus genera. Phylogenetic analyses of the P1 and 3D sequences indicated that this virus forms a distinct branch of the family Picornaviridae. On the basis of results presented in this paper PEV-1 has been assigned to a new picornavirus genus. The phylogeny of the virus in relation to other picornaviruses is discussed.