Abstract
The polypeptide coding assignments for the five messengers of the 18S size class of Newcastle disease virus (NDV) RNA have been determined by cell-free translation of individual RNAs separated by gel electrophoresis. Listed in order of their decreasing electrophoretic mobilities in acid agarose-urea gels, the coding assignments of the RNAs were as follows: RNA 1, M protein; RNA 2, P protein; RNA 3, NP; RNA 4, F glycoprotein; and RNA 5, HN glycoprotein. RNA 2 also directed the synthesis of 33- and 36-kilodalton proteins, which were tentatively identified as being overlapping segments of the P protein. The 33- and 36-kilodalton polypeptides could be detected in infected cells, but not in purified virions of NDV. Since the other unique NDV RNA, a 35S species, has been shown previously to encode the viral L protein, these results complete the coding assignments of the six known NDV mRNAs.