1S8K

Solution Structure of BmKK4, A Novel Potassium Channel Blocker from Scorpion Buthus martensii Karsch, 25 structures


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 25 
  • Selection Criteria: 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 of BmKK4, the first member of subfamily alpha-KTx 17 of scorpion toxins

Zhang, N.Chen, X.Li, M.Cao, C.Wang, Y.Wu, G.Hu, G.Wu, H.

(2004) Biochemistry 43: 12469-12476

  • DOI: 10.1021/bi0490643

  • PubMed Abstract: 
  • BmKK4 is a 30 amino acid peptide purified from the venom of the Chinese scorpion Buthus martensi Karsch. It has been classified as the first member of scorpion toxin subfamily alpha-KTx 17. The 3D structure of BmKK4 in solution has been determined by ...

    BmKK4 is a 30 amino acid peptide purified from the venom of the Chinese scorpion Buthus martensi Karsch. It has been classified as the first member of scorpion toxin subfamily alpha-KTx 17. The 3D structure of BmKK4 in solution has been determined by 2D NMR spectroscopy. This toxin adopts a common alpha/beta-motif, but shows a distinctive local conformation. The most novel feature is that the regular arrangements of the side chains of the residues involved in the beta-sheet of BmKK4 are distorted by a classic beta-bulge structure, which involves two residues (Asp18 and Arg19) in the first strand opposite a single residue (Tyr26) in the second strand. The bulge produces two main changes in the structure of the antiparallel beta-sheet: (1) It disrupts the normal alteration of the side chain direction; the side chain of Asp18 turns over to form a salt bridge with that of Arg19. (2) It accentuates the twist of the sheet, and alters the direction of the antiparallel beta-sheet. The unusual structural feature of the toxin is attributed to the shorter peptide segment (Leu15-Arg19) between the third and fourth Cys residues and two unique residues (Asp18 and Arg19) at the position preceding the fourth Cys. In addition, the lower affinity of the peptide for the Kv channel is correlated to the structural features: residue Arg19 instead of a Lys residue at the critical position for binding and the salt bridge formed between residues Arg19 and Asp18.


    Organizational Affiliation

    State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Toxin BmKK4
A
31Mesobuthus martensiiMutation(s): 0 
Find proteins for Q95NJ8 (Mesobuthus martensii)
Go to UniProtKB:  Q95NJ8
Small Molecules
Modified Residues  2 Unique
IDChainsTypeFormula2D DiagramParent
NH2
Query on NH2
A
NON-POLYMERH2 N

--

PCA
Query on PCA
A
L-PEPTIDE LINKINGC5 H7 N O3GLU
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 25 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 1S8K Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-02-08
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance