Fig. 5.

Multiple sequence alignment and three-dimensional structures of 3FTxs. Alignment of snake venom short chain (Aa-c, Taipan-1, erabutoxin a, mambalgin-2), long chain (Bungarotoxin a, acanthopin d), muscarinic toxins (MT 7), cardiotoxins (CTX V, Toxin gamma), β-cardiotoxins (β-cardiotoxin) and mammalian 3FTxs (Lynx 1, Slurp 1) using CLC Main Workbench 6. Highly conserved residues are highlighted in green while semi-conserved residues are a lighter green. The consensus sequence is shown above the multiple sequence alignment with disulfide connectivity shown in solid red lines. The fifth disulfide observed in long chain 3FTxs is linked by a dotted red line. Ribbon models A–D represent the short-chain neurotoxin erabutoxin-a (1QKE-purple ribbon), mambalgin-2 (2MFA-orange ribbon); long-chain neurotoxin alpha-bungarotoxin (1KFH-blue ribbon); cardiotoxin analogue V (CTX V) (1CHV-green ribbon); and the water-soluble domain of human LYNX1 (2L03-light blue ribbon), respectively. The conserved disulfide bridges are shown in yellow and functional residues are shown in red; 1QKE-K27, W29, D31, F32, R33, K47; 1KFH- A7, S9, I11, R36, K38, V39, V40; 1CHV- M26, K44. The added methionine of water-soluble LYNX-1 lacking the GPI anchor is shown in black