1LA4

Solution Structure of SGTx1


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the least restraint violations,structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Solution Structure and Functional Characterization of SGTx1, a Modifier of Kv2.1 Channel Gating

Lee, C.W.Kim, S.Roh, S.H.Endoh, H.Kodera, Y.Maeda, T.Kohno, T.Wang, J.M.Swartz, K.J.Kim, J.I.

(2004) Biochemistry 43: 890-897

  • DOI: 10.1021/bi0353373

  • PubMed Abstract: 
  • SGTx1 is a peptide toxin isolated from the venom of the spider Scodra griseipes that has been shown to inhibit outward K(+) currents in rat cerebellar granule neurons. Although its amino acid sequence is known to be highly (76%) homologous with that ...

    SGTx1 is a peptide toxin isolated from the venom of the spider Scodra griseipes that has been shown to inhibit outward K(+) currents in rat cerebellar granule neurons. Although its amino acid sequence is known to be highly (76%) homologous with that of hanatoxin (HaTx), a well-characterized modifier of Kv2.1 channel gating, the structural and functional characteristics of SGTx1 remain largely unknown. Here we describe the NMR solution structure of SGTx1, the mechanism of its interaction with Kv2.1 channels, and its effect on channel activity once bound. The NMR structure of SGTx1 contains a molecular fold closely resembling the "inhibitor cystine knot" of HaTx, which is composed of an antiparallel beta-sheet and four chain reversals stabilized by three disulfide bonds. Functionally, SGTx1 reversibly inhibited K(+) currents in oocytes expressing Kv2.1 channels. Moreover, generation of steady-state activation curves showed that, consistent with other gating modifiers, SGTx1 acted by shifting the activation of the channel to more depolarized voltages. Thus, the surface profile and mechanism of action of SGTx1 are similar to those of HaTx. Still, detailed comparison of SGTx1 with HaTx revealed differences in binding affinity and conformational homogeneity that result from differences in the charge distribution at the binding surface and in the amino acid composition of the respective beta-hairpin structures in the peptides.


    Organizational Affiliation

    Department of Life Science, Kwangju Institute of Science and Technology, Kwangju 500-712, Korea.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
SGTx1
A
34Stromatopelma calceatum griseipesN/A
Find proteins for P56855 (Stromatopelma calceatum griseipes)
Go to UniProtKB:  P56855
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the least restraint violations,structures with the lowest energy 
  • Olderado: 1LA4 Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-11-11
    Type: Initial release
  • Version 1.1: 2008-04-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance