5TBQ

The Solution Structure of the Magnesium-bound Conantokin-R1B Mutant

  • Classification: TOXIN
  • Organism(s): Conus rolani

  • Deposited: 2016-09-12 Released: 2017-06-28 
  • Deposition Author(s): Castellino, F.J., Yuan, Y.
  • Funding Organization(s): National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI) 

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Submitted: 20 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Discerning the Role of the Hydroxyproline Residue in the Structure of Conantokin Rl-B and Its Role in GluN2B Subunit-Selective Antagonistic Activity toward N-Methyl-d-Aspartate Receptors.

Yuan, Y.Balsara, R.D.Zajicek, J.Kunda, S.Castellino, F.J.

(2016) Biochemistry 55: 7112-7122

  • DOI: 10.1021/acs.biochem.6b00962
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Conantokins (con) are short γ-carboxyglutamate (Gla)-containing polypeptides expressed by marine snails that function as antagonists of N-methyl-d-aspartate receptor (NMDAR) ion channels. The Gla residues govern structural conformations and antagonis ...

    Conantokins (con) are short γ-carboxyglutamate (Gla)-containing polypeptides expressed by marine snails that function as antagonists of N-methyl-d-aspartate receptor (NMDAR) ion channels. The Gla residues govern structural conformations and antagonistic activities of the conantokins. In addition to Gla, some conantokins, e.g., conRl-B, also contain a hydroxyproline (HyP or O) residue, which in this case is centrally located in the peptide at position 10. Because conRl-B specifically inhibits ion channels of GluN2B subunit-containing heterotetrameric NMDARs, we evaluated the unusual role of HyP 10 in this effect. To accomplish this goal, we examined synthetic variants of conRl-B in which HyP 10 was either deleted (conRl-B[ΔO 10 ]) or replaced with alanine (conRl-B[O 10 A]) or proline (conRl-B[O 10 P]). The solution structures of these variants were determined by nuclear magnetic resonance spectroscopy. Deletion of HyP 10 , or replacement of HyP 10 with Ala 10 , attenuated the distortion in the central region of the apo-conRl-B helix and allowed Mg 2+ -complexed end-to-end α-helix formation. The inhibitory properties of these variants were assessed by measuring NMDA/Gly-stimulated intracellular Ca 2+ influx in mice neurons. ConRl-B[O 10 P] retained its NMDAR ion channel inhibitory activity in wild-type (WT) neurons but lost its GluN2B specificity, whereas conRl-B[ΔO 10 ] showed overall diminished inhibitory function. ConRl-B[O 10 A] showed attenuated inhibitory function but retained its GluN2B specificity. Thus, HyP 10 plays a critical role in maintaining the structural integrity of conRl-B, which can be correlated with its GluN2B subunit-selective inhibition. Weakened inhibition by conRl-B was also observed in neurons lacking either the GluN2C or GluN2D subunit, compared to WT neurons. This suggests that GluN2C and GluN2D are also required for inhibition by conRl-B.


    Organizational Affiliation

    W. M. Keck Center for Transgene Research and ‡Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Conantokin
A
19Conus rolaniMutation(s): 0 
Find proteins for P0DKZ0 (Conus rolani)
Go to UniProtKB:  P0DKZ0
Small Molecules
Modified Residues  2 Unique
IDChainsTypeFormula2D DiagramParent
NH2
Query on NH2
A
NON-POLYMERH2 N

--

CGU
Query on CGU
A
L-PEPTIDE LINKINGC6 H9 N O6GLU
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Submitted: 20 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)United StatesHL019982

Revision History 

  • Version 1.0: 2017-06-28
    Type: Initial release
  • Version 1.1: 2017-09-27
    Type: Author supporting evidence
  • Version 1.2: 2019-12-04
    Type: Author supporting evidence, Data collection