Two nontemplated nucleotide additions are required to generate the P mRNA of parainfluenza virus type 2 since the RNA genome encodes protein V.

The nucleotide sequence of the "P/V gene" of parainfluenza virus type 2 is presented. To determine the nature of any nontemplated additions of nucleotides that may arise during the synthesis of mRNA from this gene the polymerase chain reaction was used to amplify specific sequences of both genomic RNA and mRNA. These results demonstrated that the V protein is encoded by the genome while insertion of two nontemplated G residues are required to synthesize P mRNA. The predicted P protein has 44% identical amino acid homology with that of simian virus 5 and 37% with mumps virus; 25% of the amino acids is conserved between all three viruses.