Fig. 1

CRISPR/Cas13 orthologues for RNA virus interference. a Schematic representation of CRISPR/Cas13 variants and their respective crRNA structures. Structural representations of different Cas13 subtypes with their corresponding crRNA structures are shown with the estimated average size of the Cas13 protein under each subtype. HEPN, high eukaryotic and prokaryotic nucleotide binding domains; aa, amino acid; nt, nucleotides. b Schematic of different Cas13 protein variants used in this study. The different Cas13 variants are shown with their different fusions. NLS, nuclear localization signal; NES, nuclear export signal; GFP, green fluorescent protein. c Schematic of TRBO-based Cas13 mediated RNA virus interference. The highly replicating plant TRBO RNA virus expressing GFP protein was used as a reporter system to screen for efficient Cas13 activity in transient assays via crRNA delivered through TRV system, targeting two different regions within the GFP sequence of the virus RNA genome. 35S, CaMV 35S promoter; pPEBV, pea early browning virus promoter; RNA1/RNA2, genomes of the tobacco rattle virus (TRV)