2A AND 2A-LIKE SEQUENCES IN RNA VIRUSES: IMPLICATIONS FOR THE EVOLUTION AND COMPLEXITY OF GENOMES
2A sequences, Pseudo 2A-like, 2A-like ranking, Totiviridae family
2A/2A-like sequences are oligopeptides with approximately 18-22 amino acids characterized by a nine amino acid C-terminal motif -(G/H)1D2(V/I)3E4X5N6P7G8P9- participate in the “skip” effect of the ribosome during a translation, or which separates two proteins without the need for a proteinase. The study in question aims to identify and characterize 2A sequences in viral genomes that determine how families in which these factors occur in view of the implications of these viral evolutionary sequences and in the use of genomes and their great biotechnological applicability. For this, RdRp sequences were used to update as phylogenetic relationships of the family Totiviridae through a Bayesian analysis using the BEAST v2.4 program, or that allow the identification of a monophyletic group called expanded Giardia virus that is composed of similar subgroups IMNV and GLV type. The Foldindex program was also used to characterize genetic elements of ORF1 of viruses belonging to the expanded Giardiavirus group. In addition, in this study the ranking of type 2A was developed, or which was used to identify sequences with a high propensity to transform into 2A likes, here called pseudo 2A, among the viruses infected by arthropods of the expanded Giardiavirus group. And by making an analysis of the invisible locations of the 2A and pseudo 2A sequences of the IMNV and GLV groups, as through the DAMB program, it was possible to identify these sequences that can undergo positive and neutral changes, respectively. With that in mind and considering phylogenetic reconstruction and pseudo 2A-like we suggest that these sequences can be a precursor for a viral evolution of this family once they undergo changes and if they become functional 2A-like sequences they can use the complexity of the genome viral.