Figure 1.

C protein expression among viruses of the Paramyxoviridae family. (A) Phylogenetic tree indicating subfamilies and genera. The tree is based on full genome alignment of available reference genomes in GenBank using CLUSTALW [18] and was generated with iTOL [19]. Viruses of genera in red express C proteins. (B) Organization of the overlapping open reading frames in the mRNAs derived from the P/V/C genes of MeV (left), SeV (center) and NiV (right). SeV expresses four C proteins from alternative start codons named C’, C, Y1 and Y2. (C) Secondary structure predictions for P and C proteins, as well as the V protein-specific carboxy-terminus (V_CT). Alpha-helices are depicted in blue, beta strands in orange and unstructured (coiled) regions are shown in grey. Underlined regions in P and V proteins correspond to their unique carboxy-termini (P_CT and V_CT). N⁰BD: binding domain interacting with free nucleoprotein; TMD: tetramerization domain of P; XD: domain of P interacting with N_tail of the nucleocapsid; ZnBD: Zn-binding domain of V protein that interacts with several host innate immunity factors. Figure generated with BioRender.com.