1I02

NMR STRUCTURE OF CTX A3 AT NEUTRAL PH (20 STRUCTURES)


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 
  • Selection Criteria: The submitted structures are the 20 structures with the lowest energy. 

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This is version 1.2 of the entry. See complete history


Literature

Dynamic characterization of the water binding loop in the P-type cardiotoxin: implication for the role of the bound water molecule.

Sue, S.C.Jarrell, H.C.Brisson, J.R.Wu, W.G.

(2001) Biochemistry 40: 12782-12794

  • DOI: 10.1021/bi010848f
  • Primary Citation of Related Structures:  
    1I02

  • PubMed Abstract: 
  • Recent studies of cobra P-type cardiotoxins (CTXs) have shown that the water-binding loop (loop II) plays a crucial role in toxin binding to biological membranes and in their cytotoxicity. To understand the role of bound water in the loop, the structure and dynamics of the major P-type CTX from Taiwan cobra, CTX A3, were determined by a comprehensive NMR analysis involving (1)H NOESY/ROESY, (13)C[1)H]NOE/T(1) relaxation, and (17)O triple-quantum filtered NMR ...

    Recent studies of cobra P-type cardiotoxins (CTXs) have shown that the water-binding loop (loop II) plays a crucial role in toxin binding to biological membranes and in their cytotoxicity. To understand the role of bound water in the loop, the structure and dynamics of the major P-type CTX from Taiwan cobra, CTX A3, were determined by a comprehensive NMR analysis involving (1)H NOESY/ROESY, (13)C[1)H]NOE/T(1) relaxation, and (17)O triple-quantum filtered NMR. A single water molecule was found to be tightly hydrogen bonded to the NH of Met26 with a correlation time (5-7 ns) approaching the isotropic tumbling time (3.8-4.5 ns) of the CTX A3 molecule. Surprisingly, despite the relatively long residence time (ca. 5 ns to 100 micros), the bound water molecule of CTX A3 is located within a dynamic (order parameter S(2) approximately 0.7) and solvent accessible loop. Comparison among several P-type CTXs suggests that proline residues in the consensus sequence of MxAxPxVPV should play an important role in the formation of the water binding loop. It is proposed that the exchange rate of the bound water may play a role in regulating the lipid binding mode of amphiphilic CTX molecules near membrane surfaces.


    Organizational Affiliation

    Department of Life Sciences, National Tsing Hua University, Hsinchu 30043, Taiwan.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CARDIOTOXIN-3A60Naja atraMutation(s): 0 
UniProt
Find proteins for P60301 (Naja atra)
Explore P60301 
Go to UniProtKB:  P60301
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 
  • Selection Criteria: The submitted structures are the 20 structures with the lowest energy. 
  • OLDERADO: 1I02 Olderado

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-02-14
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance