ABSTRACT
In order to demonstrate the taxonomic position of paramyxovirus Tianjin strain and explore its mechanism of pathogenesis. Bioinformatics methods were used to analyze the deduced amino acid sequences of NP, P, M, and L protein of Tianjin strain. Phylogenetic analysis based on NP, P, M, and L protein sequences demonstrated that Tianjin strain belonged to the genus Respirovirus, in the subfamily Paramyxovirinae and most likely a new genotype of Sendai virus. Sequence similarities comparisons indicated that Tianjin strain P protein was poorly conserved, sharing only 78.7%~91.9% amino acid identity with 6 known Sendai viruses, while L protein was the most conserved, having 96.0%~98.0% amino acid identity with other Sendai viruses. Multiple-sequence alignments of Tianjin strain NP, P, M, and L protein with those of 6 known Sendai viruses showed that Tianjin strain possessed a lot of unique amino acid substitutions in protein sequences, 15 in NP, 29 in P, 6 in M, and 29 in L. The presence of these unique amino acid substitutions suggests that Tianjin strain maybe has a significant difference in host or pathological characteristics from the known Sendai viruses.