Alignment of the amino acid sequence for TSTI0109S, from T. stigmurus venom glands, with known potassium channel toxins (α-KTX). Residues are numbered according to the aligned potassium channel toxins (α-KTX) sequences and dots represent gaps introduced to improve alignment. The putative signal peptide is omitted. Conserved cystein residues are indicated by asterisks. The key lysine for blocking activity is detached by a cross. The CXXXC and CXC motifs conserved among scorpion neurotoxins are underlined. Green, red and gray indicate amino acids that are identical, conserved or similar, respectively. The abbreviation and GenBank accession number for the aligned potassium channel toxins sequences are: TsPep2, Tityus serrulatus potassium channel toxin (P0C175); Tst-17, Tityus stigmurus potassium channel toxin (P0C8X6).