Sequence comparison between the phosphoprotein mRNAs of human and bovine respiratory syncytial viruses identifies a divergent domain in the predicted protein.

The nucleotide and deduced amino acid sequences of the phosphoprotein (P) mRNA of bovine respiratory syncytial virus (BRSV) strain A51908 have been determined. The P mRNA is 860 nucleotides long with a single large open reading frame and the encoded polypeptide is 241 amino acids long. Comparison with the corresponding sequences of human respiratory syncytial virus (HRSV) subgroups A and B revealed 72 to 74% identity at the nucleotide level, and 81% at the amino acid level. The P protein contains a single divergent domain (37% amino acid identity) flanked by highly conserved domains (87% amino acid identity). The 3' end non-coding region is 47 nucleotides shorter than the corresponding region of HRSV. Comparison of the P mRNA sequences of two strains of BRSV (A51908 and FS-1) showed that there was extensive sequence identity at both the nucleotide (97%) and amino acid (97.9%) levels.