Molecular characterization of VP2 and VP3 proteins of chicken anemia virus isolates in Turkey


Abstract: Chicken anemia virus (CAV) has a circular 2.3 kb DNA genome encoding VP1, VP2, and VP3 proteins. VP1 protein is assembled into viral capsid. VP2 is a nonstructural protein required for the correct assembly of VP1. Also, there is an interaction between VP2 and VP3 protein, known as apoptin. Mostly, VP1 protein of CAV isolates have been investigated in previous studies but the information about VP2 and VP3 proteins is insufficient. The aim of this study is molecular characterization of VP2 and VP3 proteins from 20 CAV isolates previously collected in different regions of Turkey using in silico tools. The open reading frames (ORFs) for VP2 and VP3 were determined to be 651 and 366 base pairs (bp) encoding 216 and 121 amino acids, respectively. Nucleotide substitutions were identified at 21 and 14 positions for VP2 and VP3, respectively. Three isolates had one apiece amino acid substitutions in VP2 sequences. The MW and pI values for VP2 were predicted as 24.08?24.138 kDa and 6.96?8.35, respectively. Moreover, seven isolates had one to three amino acid substitutions for VP3 protein. The MW and pI values for VP3 were calculated as 13.188-13.372 kDa and 9.44-9.95, respectively. The secondary structures were predicted and phylogenetic trees were constructed for VP2 and VP3 proteins. As a conclusion, molecular characterization of VP2 and VP3 proteins from 20 CAV isolates contributes to the current knowledge on these proteins having diverse functions and immunological potentials.

Keywords: Bioinformatics, chicken anemia virus, VP2, VP3

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