Sequence conservation in A46 and related families. (A) Multiple sequence alignment with the common sequence domain found in protein families A46, N1, N2 and C1. The alignment is non-redundant at 90% sequence identity. Sequences are identified by species/strain and gene locus number: SWPV-NEB, swinepox virus strain Nebraska 17077-99; SPPV-TU, sheeppox virus strain TU-V02127; DPV-W848_83, deerpox virus strain W-848-83; MYXV-LAU, myxoma virus strain Lausanne; RFV-KAS, rabbit fibroma virus strain Kasza; VACV-WR, vaccinia virus strain Western Reserve; YLDV-Davis, yaba-like disease virus strain Davis; RPXV-UTR, rabbitpox virus strain Utrecht; LSDV-NW_LW, lumpy skin disease virus strain Neethling Warmbaths LW; ECTV-NAV, ectromelia virus strain Naval. Shading indicates degree of sequence similarity. Conserved motifs are indicated with horizontal bars on the top of the alignment. Predicted secondary structure is indicated below each block of sequences (orange: alpha-helix; blue: beta-sheet), except for A46 and N1, for which secondary structures of A52 (PDB:2VVW) and N1 (PDB:2I39), respectively, are shown. Green arrowheads indicate N1 protein residues putatively involved in BH3 peptide binding . (B) Structural distribution of conserved motifs. Conserved residues in the multiple sequence alignment were mapped on the N1 structure (PDB:2I39). Secondary structure elements are depicted in yellow, except conserved residues, in orange. Side chains are coloured in red. Surface is shown in light grey. Structures were rendered with UCSF Chimera .