Heliyon (Apr 2023)
Analysis on the genome of a teschovirus type 1 isolates with swine diarrhea
Abstract
Porcine Teschoviruses (PTVs) are associated with polioencephalomyelitis and various diseases, including reproductive and gastrointestinal disorders of pigs and wild boars, but rarely detected in the feces of pigs. In this study, a sample of swine diarrhea that tested positive for PTVs is subjected to high-throughput sequencing. The viral genome was 7221 nucleotides (nt) in length, which was consisted of twelve genes. Phylogenetic analysis showed and it was closely related to the PTV-HNMY(MG755212.1). The nucleotide homology of VP1 gene of PTVs JS2021 with PTV-1AF 296102.1 reached 82.97%, belonging to a branch of PTV-1 serotype. The nucleotide homology of VP1 protein with other serotypes of PTV is quite different from that of other serotypes of PTV. Bioinformatics analysis showed that PTVs have four capsid proteins, namely VP1, VP2, VP3 and VP4. The VP1 encodes a 29 kDa protein, which is the main protective antigen, a theoretical isoelectric point of 6.73, no transmembrane domain, no signal peptide and potential phosphorylation site. The VP1 protein is an unstable hydrophilic intracellular protein, which contains four secondary structures: irregular curl (c), extended chain (e), α-helix (h) and β-folded (t). The tertiary structure is heart-shaped and has multiple B cell epitopes. By analyzing the tertiary structure, we found that the amino acid at position 129 of VP1 mutated and reduction a larger alpha helix. This may lead to the main cause of piglet diarrhea. These findings enriched our knowledge of the viruses in the role of swine diarrhea, and help to develop an effective strategy for disease prevention and control.
