Macromolecule Content

• Total Structure Weight: 3.79 kDa 
• Atom Count: 259 
• Modelled Residue Count: 34 
• Deposited Residue Count: 34 
• Unique protein chains: 1

1LA4

Solution Structure of SGTx1

• DOI: 10.2210/pdb1LA4/pdb

• Classification: TOXIN
• Mutation(s): No 


• Deposited: 2002-03-28 Released: 2003-11-11 
• Deposition Author(s): Lee, C.W., Roh, S.H., Kim, S., Endoh, H., Kodera, Y., Maeda, T., Swartz, K.J., Kim, J.I.

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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 

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

• PubMed: 14744131 
• DOI: 10.1021/bi0353373
• Primary Citation of Related Structures:  
  1LA4


• 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 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.

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Organizational Affiliation: 

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

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
SGTx1	A	34	N/A	Mutation(s): 0
Find proteins for P56855 (Stromatopelma calceatum griseipes) Explore P56855  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

Entry History 

Deposition Data

• Deposited Date: 2002-03-28 
• Released Date: 2003-11-11 
Deposition Author(s): Lee, C.W., Roh, S.H., Kim, S., Endoh, H., Kodera, Y., Maeda, T., Swartz, K.J., Kim, J.I.

Revision History  

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