NMR structure of OtTx1a - AMP in DPC micelles

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: target function 

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Modular toxin from the lynx spider Oxyopes takobius: Structure of spiderine domains in solution and membrane-mimicking environment.

Nadezhdin, K.D.Romanovskaia, D.D.Sachkova, M.Y.Oparin, P.B.Kovalchuk, S.I.Grishin, E.V.Arseniev, A.S.Vassilevski, A.A.

(2017) Protein Sci 26: 611-616

  • DOI: https://doi.org/10.1002/pro.3101
  • Primary Citation of Related Structures:  
    2N85, 2N86

  • PubMed Abstract: 

    We have recently demonstrated that a common phenomenon in evolution of spider venom composition is the emergence of so-called modular toxins consisting of two domains, each corresponding to a "usual" single-domain toxin. In this article, we describe the structure of two domains that build up a modular toxin named spiderine or OtTx1a from the venom of Oxyopes takobius. Both domains were investigated by solution NMR in water and detergent micelles used to mimic membrane environment. The N-terminal spiderine domain OtTx1a-AMP (41 amino acid residues) contains no cysteines. It is disordered in aqueous solution but in micelles, it assumes a stable amphiphilic structure consisting of two α-helices separated by a flexible linker. On the contrary, the C-terminal domain OtTx1a-ICK (59 residues) is a disulfide-rich polypeptide reticulated by five S-S bridges. It presents a stable structure in water and its core is the inhibitor cystine knot (ICK) or knottin motif that is common among single-domain neurotoxins. OtTx1a-ICK structure is the first knottin with five disulfide bridges and it represents a good reference for the whole oxytoxin family. The affinity of both domains to membranes was measured with NMR using titration by liposome suspensions. In agreement with biological tests, OtTx1a-AMP was found to show high membrane affinity explaining its potent antimicrobial properties.

  • Organizational Affiliation

    M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya, Moscow, 117997, Russia.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Spiderine-1a41Oxyopes takobiusMutation(s): 0 
Membrane Entity: Yes 
Find proteins for P86716 (Oxyopes takobius)
Explore P86716 
Go to UniProtKB:  P86716
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP86716
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: target function 

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2016-10-05
    Type: Initial release
  • Version 1.1: 2019-04-17
    Changes: Data collection, Database references
  • Version 1.2: 2023-06-14
    Changes: Data collection, Database references, Other
  • Version 1.3: 2024-05-15
    Changes: Data collection, Database references