1I25

Three dimensional solution structure of huwentoxin-II by 2D 1H-NMR

Summary for 1I25

• Entry DOI: 10.2210/pdb1i25/pdb
• NMR Information: BMRB: 4988
• Descriptor: HUWENTOXIN-II (1 entity in total)
• Functional Keywords: neurotoxin, insecticidal toxin, disulfide bonds, toxin
• Biological source: Ornithoctonus huwena (Chinese earth tiger)
• Cellular location: Secreted : P82959
• Total number of polymer chains: 1
• Total formula weight: 4300.25

Authors

Shu, Q.,Lu, S.Y.,Gu, X.C.,Liang, S.P. (deposition date: 2001-02-06, release date: 2001-02-14, Last modification date: 2024-11-06)

Primary citation

Shu, Q.,Lu, S.Y.,Gu, X.C.,Liang, S.P.
The structure of spider toxin huwentoxin-II with unique disulfide linkage: evidence for structural evolution.
Protein Sci., 11:245-252, 2002

PubMed Abstract: The three-dimensional structure of huwentoxin-II (HWTX-II), an insecticidal peptide purified from the venom of spider Selenocosmia huwena with a unique disulfide bond linkage as I-III, II-V, and IV-VI, has been determined using 2D (1)H-NMR. The resulting structure of HWTX-II contains two beta-turns (C4-S7 and K24-W27) and a double-stranded antiparallel beta-sheet (W27-C29 and C34-K36). Although the C-terminal double-stranded beta-sheet cross-linked by two disulfide bonds (II-V and IV-VI in HWTX-II, II-V and III-VI in the ICK molecules) is conserved both in HWTX-II and the ICK molecules, the structure of HWTX-II is unexpected absence of the cystine knot because of its unique disulfide linkage. It suggests that HWTX-II adopts a novel scaffold different from the ICK motif that is adopted by all other spider toxin structures elucidated thus far. Furthermore, the structure of HWTX-II, which conforms to the disulfide-directed beta-hairpin (DDH) motif, not only supports the hypothesis that the ICK is a minor elaboration of the more ancestral DDH motif but also suggests that HWTX-II may have evolved from the same structural ancestor.

PubMed: 11790834
DOI: 10.1110/ps.30502

Experimental method

SOLUTION NMR