Sequence of the nucleocapsid gene and genome and antigenome promoters for an isolate of porpoise morbillivirus

Abstract

We have determined the first complete sequence of the nucleocapsid (N) gene of the porpoise morbillivirus (PMV) as well as the genome leader and trailer sequences which encode the genome and antigenome promoters, respectively. The PMV N gene is 1686 nucleotides long with a single open reading frame (ORF) encoding a protein of 523 amino acids with a predicted molecular weight of 57.39 kDa. The nucleotide sequence of the N gene shows the closest identity (89%) to that of another cetacean morbillivirus, dolphin morbillivirus (DMV). Lower degrees of identity were found with the other members of the morbilliviruses genus; 67% identity to PDV and RPV, 68% to PPRV, 69% to CDV and 70% to MV. The distance from the 3′ end of the genome up to the start of the N ORF is 107 nucleotides, identical to that found in all other morbilliviruses, and encompasses the genome promoter (GP) sequence. This promoter shows the same regions of conservation as found in other morbilliviruses with repeated CXXXXX motifs at positions 79–84, 85–90, and 91–96, the same bi-partite promoter arrangement found in many paramyxoviruses. The antigenome promoter (AGP) shows a similar arrangement, indicating a high degree of conservation in these functionally important regions.