AMINO ACID SEQUENCE CONSERVATION AND EVOLUTION OF BACULOVIRUS PER ORAL INFECTIVITY FACTORS 1, 2 AND 3
The relationship between amino acid sequences of PIF1, PIF2 and PIF3 of baculovirus and other invertebrate DNA viruses were determined by retrieving their amino acid sequences from National Center for Biotechnology Information. The amino acid sequences were aligned in MEGA7 and analyzed for motif conservation using MEME suite. Structural modelling of these PIFs was performed in iTASSER and their amino acid sequences phylogenetically analyzed by MEGA7. It was revealed by multiple protein sequence alignment that PIF1 was most conserved at the N-terminal end, PIF2 was most conserved in its central region, while PIF3 was most conserved at the C-terminal end. These PIFs had amino acid motifs conserved in Baculoviridae and other invertebrate DNA viruses from Nimaviridae, Hytrosaviridae and Nudiviridae highlighting a probable shared virus entry mechanism among these virus families. Structural modelling of these PIFs produced 2 distinct bulbs for PIF1, 4 distinct bulbs for PIF2 while PIF3 was largely indistinct. Phylogenetic analyses on protein sequences of PIF1, 2 and 3 from Baculoviridae, Nimaviridae, Hytrosaviridae and Nudiviridae yielded similar clustering strongly suggesting co-evolutionary conservation of these PIFs. All the bioinformatics analyses applied in this study have revealed new information of PIF1, PIF2 and PIF3 which can be attributed to their individual and collective functions as oral infectivity factors. In addition, several hypotheses for further investigation of PIFs to gain understanding on their role in oral infectivity and biocontrol of insects have been raised.