Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Submitted: 17 

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This is version 1.3 of the entry. See complete history


Solution structure of the potassium channel inhibitor agitoxin 2: caliper for probing channel geometry.

Krezel, A.M.Kasibhatla, C.Hidalgo, P.MacKinnon, R.Wagner, G.

(1995) Protein Sci 4: 1478-1489

  • DOI: https://doi.org/10.1002/pro.5560040805
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The structure of the potassium channel blocker agitoxin 2 was solved by solution NMR methods. The structure consists of a triple-stranded antiparallel beta-sheet and a single helix covering one face of the beta-sheet. The cysteine side chains connecting the beta-sheet and the helix form the core of the molecule. One edge of the beta-sheet and the adjacent face of the helix form the interface with the Shaker K+ channel. The fold of agitoxin is homologous to the previously determined folds of scorpion venom toxins. However, agitoxin 2 differs significantly from the other channel blockers in the specificity of its interactions. This study was thus focused on a precise characterization of the surface residues at the face of the protein interacting with the Shaker K+ channel. The rigid toxin molecule can be used to estimate dimensions of the potassium channel. Surface-exposed residues, Arg24, Lys27, and Arg31 of the beta-sheet, have been identified from mutagenesis studies as functionally important for blocking the Shaker K+ channel. The sequential and spatial locations of Arg24 and Arg31 are not conserved among the homologous toxins. Knowledge on the details of the channel-binding sites of agitoxin 2 formed a basis for site-directed mutagenesis studies of the toxin and the K+ channel sequences. Observed interactions between mutated toxin and channel are being used to elucidate the channel structure and mechanisms of channel-toxin interactions.

  • Organizational Affiliation

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
AGITOXIN 238Leiurus quinquestriatus hebraeusMutation(s): 0 
Gene Names: AGTX2
Find proteins for P46111 (Leiurus hebraeus)
Explore P46111 
Go to UniProtKB:  P46111
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UniProt GroupP46111
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Submitted: 17 

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1995-07-10
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-11-29
    Changes: Derived calculations, Other