Crystal structure of CRY4BA-R203Q TOXIN

Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.216 
  • R-Value Observed: 0.220 

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This is version 1.2 of the entry. See complete history


Potential Prepore Trimer Formation by the Bacillus thuringiensis Mosquito-specific Toxin: MOLECULAR INSIGHTS INTO A CRITICAL PREREQUISITE OF MEMBRANE-BOUND MONOMERS

Sriwimol, W.Aroonkesorn, A.Sakdee, S.Kanchanawarin, C.Uchihashi, T.Ando, T.Angsuthanasombat, C.

(2015) J Biol Chem 290: 20793-20803

  • DOI: https://doi.org/10.1074/jbc.M114.627554
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The insecticidal feature of the three-domain Cry δ-endotoxins from Bacillus thuringiensis is generally attributed to their capability to form oligomeric pores, causing lysis of target larval midgut cells. However, the molecular description of their oligomerization process has not been clearly defined. Here a stable prepore of the 65-kDa trypsin-activated Cry4Ba mosquito-specific toxin was established through membrane-mimetic environments by forming an ∼200-kDa octyl-β-D-glucoside micelle-induced trimer. The SDS-resistant trimer caused cytolysis to Sf9 insect cells expressing Aedes-mALP (a Cry4Ba receptor) and was more effective than a toxin monomer in membrane perturbation of calcein-loaded liposomes. A three-dimensional model of toxin trimer obtained by negative-stain EM in combination with single-particle reconstruction at ∼5 nm resolution showed a propeller-shaped structure with 3-fold symmetry. Fitting the three-dimensional reconstructed EM map with a 100-ns molecular dynamics-simulated Cry4Ba structure interacting with an octyl-β-D-glucoside micelle showed relative positioning of individual domains in the context of the trimeric complex with a major protrusion from the pore-forming domain. Moreover, high-speed atomic force microscopy imaging at nanometer resolution and a subsecond frame rate demonstrated conformational transitions from a propeller-like to a globularly shaped trimer upon lipid membrane interactions, implying prepore-to-pore conversion. Real-time trimeric arrangement of monomers associated with L-α-dimyristoylphosphatidylcholine/3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxy-1-propanesulfonic acid bicelle membranes was also envisaged by successive high-speed atomic force microscopy imaging, depicting interactions among three individual subunits toward trimer formation. Together, our data provide the first pivotal insights into the structural requirement of membrane-induced conformational changes of Cry4Ba toxin monomers for the molecular assembly of a prepore trimer capable of inserting into target membranes to generate a lytic pore.

  • Organizational Affiliation

    Department of Physics and Bio-AFM Frontier Research Center, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Pesticidal crystal protein cry4Ba602Bacillus thuringiensis serovar israelensisMutation(s): 1 
Gene Names: cry4Babt8cryD2cryIVB(a)isrH3
Find proteins for P05519 (Bacillus thuringiensis subsp. israelensis)
Explore P05519 
Go to UniProtKB:  P05519
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP05519
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.216 
  • R-Value Observed: 0.220 
  • Space Group: H 3 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 184.618α = 90
b = 184.618β = 90
c = 187.359γ = 120
Software Package:
Software NamePurpose
ADSCdata collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-12-10
    Type: Initial release
  • Version 1.1: 2016-12-14
    Changes: Database references
  • Version 1.2: 2023-11-08
    Changes: Data collection, Database references, Refinement description