Sequence of calliotoxin (δ-elapitoxin-Cb1a) and the most closely related three-finger toxins. Homology to known three-finger toxins (3FTxs) was determined using BLAST and multiple sequence alignment conducted with CLUSTAL Omega (1.2.2). Calliotoxin (δ-elapitoxin-Cb1a; blue sequence) is most closely related to ρ-EPTX-Dp1b (P25518.1; Dendroaspis polylepis polylepis; 50% sequence identity), ρ-EPTX-Dp1a (P80495.1; Dendroaspis polylepis polylepis; 50% sequence identity), ρ-EPTX-Da1a (P85092.1; Dendroaspis angusticeps; 49% sequence identity), and ρ-EPTX-Da1b (P86419.1; Dendroaspis angusticeps; 53% sequence identity), three-finger toxins with activity at α1-adrenoreceptors, as well as muscarinic toxin 3 (P81031.2; Dendroaspis angusticeps; 49% sequence identity) targeting the mAChR and Toxin CM-12 (P62394.1; Naja haje haje; 42% sequence identity), Cardiotoxin 7 (P49122.1; Naja atra; 42% sequence identity), and Three-finger toxin 6 (JAS05190.1; Micrurus tener; 47% sequence identity) with unknown pharmacological activity. Conserved ancestral cysteines shown in bold, disulphide-bond pattern shown in black lines.