Figure 1

Relationship between the putative capsid proteins of amalgaviruses and nucleocapsid proteins of tenuiviruses and phleboviruses. A. Pairwise identity plot of capsid and nucleocapsid proteins of amalgaviruses, tenuiviruses and phleboviruses. Protein accession numbers are provided in panel D, whereas the full virus names are provided in the Abbreviations section. B. Schematic representation of the putative capsid protein of rhododendron virus A (RhVA). The proline/glycine-rich N- and C-terminal domains (PG- and PG+, respectively) are shown in grey, whereas the central domain showing similarity to the nucleocapsid proteins of phleboviruses and tenuiviruses (Tenui/Phlebo NC) is in green. Blue and red ticks above and below the scheme indicate the positions of positively (Arg, Lys) and negatively (Asp, Glu) charged amino acid residues, respectively, whereas yellow streaks correspond to Pro and Gly residues. The table includes the counts and percentages of Asp/Glu (D/E), Arg/Lys (R/K) and Pro/Gly (P/G) residues in the respective domains. C. X-ray structure of the nucleocapsid protein of Severe fever with thrombocytopenia syndrome virus (SFTSV). Amino acid residues shared with RhVA CP are shown in blue, regions that have counterparts in RhVA but do not show close sequence similarity are shown in orange, and regions that are absent in the RhVA protein are shown in grey. The residues important for RNA-binding are shown with ball-and-stick representation. The ‘Core’ and ‘Helical arm’ domains are indicated. D. Multiple sequence alignment of RhVA CP with tenuiviral and phleboviral NC homologs. Sequences are identified with UniProt or PDB accession numbers followed by abbreviated virus names. Above the alignment are the predicted (for RhVA) and experimentally determined (for SFTSV) secondary structure elements; α-helices, red ellipses; β-strands, blue arrows. The alignment is colored according to sequence conservation using the standard Clustal color scheme.