9QXQ | pdb_00009qxq

native structure of full-length pesticidal protein Cry1Ca18 at pH9, from crystals formed in vivo


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Free: 
    0.206 (Depositor), 0.213 (DCC) 
  • R-Value Work: 
    0.178 (Depositor), 0.186 (DCC) 
  • R-Value Observed: 
    0.179 (Depositor) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

Validation slider image for 9QXQ

This is version 1.1 of the entry. See complete history

Literature

The long and short of it: Distinct natural crystal packing strategies of Cry toxins from Bacillus thuringiensis.

Best, H.L.Williamson, L.J.Cutts, A.B.Galchenkova, M.Yefanov, O.Bryce-Sharron, N.Heath, E.A.de Wijn, R.Schubert, R.Munke, A.Henkel, A.Klopprogge, B.Scheer, T.E.S.Kremling, V.Awel, S.Pena, G.Knoska, J.Keloth, A.Maracke, J.Letrun, R.Sobolev, E.Bielecki, J.Melo, D.Kantamneni, S.Doerner, K.Kloos, M.Schulz, J.Xavier, P.L.Lauffer, M.Villanueva, M.Caballero, P.Waller-Evans, H.Lloyd-Evans, E.Uetrecht, C.Bean, R.Chapman, H.N.Crickmore, N.Rizkallah, P.J.Berry, C.Oberthur, D.

(2026) Structure 

  • DOI: https://doi.org/10.1016/j.str.2026.01.014
  • Primary Citation Related Structures: 
    9H99, 9H9A, 9H9B, 9QXQ

  • PubMed Abstract: 

    Bacillus thuringiensis (Bt) strains naturally produce pesticidal proteins as nanocrystalline inclusions that are extraordinarily stable in aqueous environments, but which dissolve selectively at specific pH conditions. These proteins have been used in agriculture for >50 years and are critical to global food security. The majority of previously determined Bt Cry protein structures lack the extended C-terminal "crystallization domain," which is thought to stabilize crystal packing and control selective solubility in insect targets, often via manipulation of disulfide bridges. It has also recently been shown to influence toxicity and target specificity. Here, we use serial femtosecond crystallography (SFX) to determine high-resolution full-length native structures of Cry1Ca18 (1.65 Å) and Cry8Ba2 (2.27 Å) in their natural nanocrystalline state. Differences in cysteine content (19 versus 4 residues) reveal distinct in vivo crystal-stabilization strategies. Understanding Bt toxin domain architecture and natural crystal formation is essential for improving biopesticide design and advancing agricultural genetic engineering.


  • Organizational Affiliation
    • School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK; Medicines Discovery Institute, Cardiff University, Cardiff CF10 3AX, UK.

Macromolecule Content 

  • Total Structure Weight: 134.96 kDa 
  • Atom Count: 9,526 
  • Modeled Residue Count: 1,061 
  • Deposited Residue Count: 1,189 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Crystaline entomocidal protoxin1,189Bacillus thuringiensisMutation(s): 0 
UniProt
Find proteins for Q9L877 (Bacillus thuringiensis)
Explore Q9L877 
Go to UniProtKB:  Q9L877
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9L877
Sequence Annotations
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Reference Sequence

Small Molecules

Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
CSO
Query on CSO
A
L-PEPTIDE LINKINGC3 H7 N O3 SCYS

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Free:  0.206 (Depositor), 0.213 (DCC) 
  • R-Value Work:  0.178 (Depositor), 0.186 (DCC) 
  • R-Value Observed: 0.179 (Depositor) 
Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 88.8α = 90
b = 88.8β = 90
c = 267.82γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
CrystFELdata scaling
PHASERphasing
PDB_EXTRACTdata extraction
CrystFELdata reduction

Structure Validation

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Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Biotechnology and Biological Sciences Research Council (BBSRC)United KingdomBB/S002774/1
Biotechnology and Biological Sciences Research Council (BBSRC)United KingdomBB/M009122/1

Revision History  (Full details and data files)

  • Version 1.0: 2026-02-11
    Type: Initial release
  • Version 1.1: 2026-03-04
    Changes: Database references