Three-finger toxins (3FTxs) of B. flaviceps venom gland cDNA library. Similar sequences were clustered together and a representative of the each cluster is presented. B. flaviceps 3FTxs can be classified into eight major groups A through H. The deduced amino acid sequences of 3FTX isoforms of each group are shown. The amino residues which are different from the representative major isoform are shaded. The predicted signal peptide of the transcripts is shown bold. The major isoforms from each group is aligned with closely related 3FTx found in the database and the % identity and similarly are also shown. (A and B) Groups A and B are similar to candiduxin1 (Q8AY53.1) and buntoxin. Group B toxins are closer to candiduxin compared to group A toxins. C) Putative short-chain 3FTxs of B. flaviceps that are similar to 3FTx (ABX82864.1) from W.aegyptia and erabutoxin a (P60775.1). The residues of erabutoxin a that are involved in binding to nAChR receptor are shown in *. Critical functional residues in BF748 are replaced with Met, Phe and Asn (27th, 29th and 47th residues respectively). D) Group D toxins are similar to bucain (Q9YGI8.1). E) Group E non-conventional 3FTx and its alignment with candoxin (P81783.2). F) Group F non-conventional 3FTx and alignment with NTX4_BUNCA (Q6IZ95.1) and NXW1_BUNCA (Q8AY51.1). G) Group G non-conventional 3FTx and its alignment with BM14 (Q8JFX7.1) and bulongin. H) Group H 3FTx and its alignment with NXL2_BUNFL (κ-favitoxin) (P15815.1) (for details, see text).
Siang et al. BMC Molecular Biology 2010 11:24 doi:10.1186/1471-2199-11-24