PDBsum entry 1d1h

Toxin

PDB id: 1d1h

Contents

Protein chain

35 a.a.

PDB id:

1d1h

Name:

Toxin

Title:

Solution structure of hanatoxin 1

Structure:

Hanatoxin type 1. Chain: a

Source:

Grammostola rosea. Organism_taxid: 432528. Tissue: venom

NMR struc:

21 models

Authors:

H.Takahashi,J.I.Kim,K.Sato,K.J.Swartz,I.Shimada

Key ref:

H.Takahashi et al. (2000). Solution structure of hanatoxin1, a gating modifier of voltage-dependent K(+) channels: common surface features of gating modifier toxins. J Mol Biol, 297, 771-780. PubMed id: 10731427 DOI: 10.1006/jmbi.2000.3609

Date:

16-Sep-99 Release date: 20-Sep-00

Protein chain

P56852  (TXHN1_GRARO) -  Kappa-theraphotoxin-Gr1a from Grammostola rosea

Seq: 85 a.a.

Struc: 35 a.a.

DOI no: 10.1006/jmbi.2000.3609

J Mol Biol 297:771-780 (2000)

PubMed id: 10731427

Solution structure of hanatoxin1, a gating modifier of voltage-dependent K(+) channels: common surface features of gating modifier toxins.

H.Takahashi, J.I.Kim, H.J.Min, K.Sato, K.J.Swartz, I.Shimada.

ABSTRACT

The three-dimensional structure of hanatoxin1 (HaTx1) was determined by using NMR spectroscopy. HaTx1 is a 35 amino acid residue peptide toxin that inhibits the drk1 voltage-gated K(+) channel not by blocking the pore, but by altering the energetics of gating. Both the amino acid sequence of HaTx1 and its unique mechanism of action distinguish this toxin from the previously described K(+) channel inhibitors. Unlike most other K(+) channel-blocking toxins, HaTx1 adopts an "inhibitor cystine knot" motif and is composed of two beta-strands, strand I for residues 19-21 and strand II for residues 28-30, connected by four chain reversals. A comparison of the surface features of HaTx1 with those of other gating modifier toxins of voltage-gated Ca(2+) and Na(+) channels suggests that the combination of a hydrophobic patch and surrounding charged residues is principally responsible for the binding of gating modifier toxins to voltage-gated ion channels.

Selected figure(s)

Figure 6.
Figure 6. (a) Surface profile of HaTx1. (b) Stereo view of the backbone and side-chain heavy atoms of HaTx1. In (a) and (b), hydrophobic residues (Ala, Cys, Ile, Leu, Met, Phe, Pro, Trp, Tyr and Val) are green; basic (Arg and Lys) and acidic (Asp and Glu) residues are blue and red, respectively. The residues in the surface hydrophobic patch and the surrounding charged residues are labeled.

Figure 7.
Figure 7. Comparison of surface profile between (a) CsE-V (PDB code 1NRA) and (b) ATX III (PDB code 1ANS). The color code is the same as that of Figure 6. The residues which belong to a hydrophobic patch and surrounding basic residues are labeled.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2000, 297, 771-780) copyright 2000.

Figures were selected by an automated process.