4MOA

Crystal structure of CRY4BA-R203Q TOXIN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.216 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

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: 10.1074/jbc.M114.627554

  • 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 o ...

    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

    From the Department of Clinical Chemistry, Faculty of Medical Technology and Bacterial Protein Toxin Research Cluster, Institute of Molecular Biosciences, Mahidol University, Nakornpathom 73170, Thailand.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Pesticidal crystal protein cry4Ba
A
602Bacillus thuringiensis subsp. israelensisMutation(s): 1 
Gene Names: cry4Ba (bt8, cryD2, cryIVB(a), isrH3)
Find proteins for P05519 (Bacillus thuringiensis subsp. israelensis)
Go to UniProtKB:  P05519
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.216 
  • Space Group: H 3 2
Unit Cell:
Length (Å)Angle (°)
a = 184.618α = 90.00
b = 184.618β = 90.00
c = 187.359γ = 120.00
Software Package:
Software NamePurpose
HKL-2000data scaling
HKL-2000data reduction
CNSrefinement
CNSphasing
ADSCdata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-12-10
    Type: Initial release
  • Version 1.1: 2016-12-14
    Type: Database references