A NOVEL P V/C GENE IN A NEW MEMBER OF THE PARAMYXOVIRIDAE FAMILY, WHICH CAUSES LETHAL INFECTION IN HUMANS, HORSES, AND OTHER ANIMALS/

In 1994, a new member of the family Paramyxoviridae isolated from fata l cases of respiratory disease In horses and humans was shown to be di stantly related to morbilliviruses and provisionally called equine mor billivirus (K. Murray et al., Science 268:94-97, 1995), To facilitate characterization and classification, the virus was purified, viral pro teins were identified, and the P/V/C gene was cloned and sequenced, Th e coding strategy of the gene is similar to that of Sendai and measles viruses, members of the Paramyxovirus and Morbillivirus genera, respe ctively, in the subfamily Paramyxovirinae. The P/V/C gene contains fou r open reading frames, three of which, P, C, and V, have Paramyxovirin ae counterparts, The P and C proteins are larger and smaller, respecti vely, than are cognate proteins in members of the subfamily, and the V protein is made as a result of a single G insertion during transcript ion, The P/V/C gene has two unique features, (i) A fourth open reading frame is located between those of the C and V proteins and potentiall y encodes a small basic protein similar to those found in some members of the Rhabdoviridae and Filoviridae families, (ii) There is also a l ong untranslated 3' sequence, a feature common in Filoviridae members, Sequence comparisons confirm that although the virus is a member of t he Paramyxovirinae subfamily, it displays only low levels of homolog w ith paramyxoviruses and morbilliviruses and negligible homologies with rubulaviruses.