Naja naja oxiana Cobra Venom Cytotoxins CTI and CTII Disrupt Mitochondrial Membrane Integrity: Implications for Basic Three-Fingered Cytotoxins
Fig 1
CLUSTAL 2.1 multiple amino acid sequence alignment of cobra venom cytotoxins.
A. Amino acid sequence alignment of cobra venom cytotoxins, with resolved crystal structures, include 2CDX from Naja naja atra, 1ZAD (CTI/Vc1, underlined): Naja naja oxiana, 1CDT: Naja mossambica mossambica, 1CRE from Naja naja atra, 4OM5 from Naja naja atra, 2CRT from Naja naja atra, 1CB9 (CTII/Vc5, underlined) from Naja naja oxiana, 1UG4 from Naja naja atra, 2CCX from Naja mossambica mossambica, 1CVO from Naja naja atra. Conserved Cys residues are highlighted in yellow. Basic and acidic residues are highlighted in red and blue respectively. The amino acid residues located within each of the three loops (I-III) are highlighted in gray below the amino acid sequences. The variable residues Ser28 and Pro30 in loop 2, characteristic of S and P-type cytotoxins respectively, are highlighted in green. The hydrophobic residues of the three loops are bolded. The overall charge and isoelectric point (PI) value for each cytotoxin are shown in two columns to the right of the amino acid alignment. B. Ribbon diagrams of the crystal structures of CTI (PDB#1ZAD) and CTII (PDB#1CB9). All basic amino acid residues are represented as stick representations and labeled accordingly (Lys: lysine, Arg: arginine).