A hidden gene in astroviruses encodes a cell-permeabilizing protein involved in virus release

Valeria Lulla; Andrew E. Firth

Interestingly, we also detected synonymous site conservation in two subgroups of genogroup II astroviruses ( Fig. S3G; Fig. S3H ). In subgroup "IId", the conservation coincided with a conserved overlapping +1 frame ORF (Fig. S5E) ; however in subgroup "IIc", there was no conserved ORF in the +1 reading frame. Instead, we observed an ORF in the −1 reading frame . CC-BY 4.0 International license author/funder. It is made available under a The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/661579 doi: bioRxiv preprint with no AUG codon (ORFY, Fig. S5D ) but with conserved signals for −1 programmed ribosomal frameshifting 10 , namely a conserved A_AAA_AAZ (Z = A, C or U) slippery heptanucleotide and a 3′-adjacent RNA stem-loop (or pseudoknot structure) (Fig. S6 ). It seems plausible that ORFX and ORFY in genogroup II astroviruses may have evolved independently of ORFX in other astrovirus genogroups (see Discussion).