Figure 1: Genome organization of STMV.

(A) Genome organization of Satellite tobacco mosaic virus (STMV) highlighting the 25 N-terminal amino acids (aa) of its coat protein ORF. The positively charged arginine (R) and lysine (K) residues are highlighted in red. (B) Graphic representation of the disordered probability of the 159 aa residues of STMV CP was by DisProt analysis. The hatched region indicates a previously identified RNA-binding domain (see text for details). In the bottom panel, aa having a score equal or above 0.5 and below 0.5 are considered to be disordered and ordered, respectively. (C) T-DNA based agro-constructs of STMV and its CP derivatives. Characteristic features of agroconstructs pRP and pSTMV were described previously⁹. CPKO, an STMV CP variant is characterized by having a ¹⁶²UAG¹⁶⁴ stop codon in the place of an¹⁶²AUG¹⁶⁴ start codon. CP variant CPΔ13aa was engineered to express CP lacking the N-terminal 13aa motif due to the presence of a stop codon between nt 162–164 (¹⁶²UAG¹⁶⁴⁾ and a start codon between nt 200–202 (²⁰⁰AUG²⁰²). CP variant CP13aa is engineered to express only the N-terminal 13aa motif by having a stop codon at amino acid position 14 located between nt 200–202 (²⁰⁰UAG²⁰²). Each agroconstruct contains in sequential order (L to R), double Cauliflower mosaic virus (CaMV) 35S promoters (indicated by arrowheads), a ribozyme (R, indicated by a bent arrow) derived from Tobacco ring spot virus (TRSV) and a NOS terminator (T). The size in nucleotides (nt) of ectopically expressed RNA transcripts and the expected nature of proteins in each case are shown to the right. The numbers shown in parentheses are the numbers of non-viral RNA nucleotides left after self-cleavage by the ribozyme (R).