8Q6I | pdb_00008q6i

Cholera holotoxin variant (chimera with E. coli heat-labile enterotoxin, 1 C-terminal substitution)

• PDB DOI: https://doi.org/10.2210/pdb8Q6I/pdb

• Classification: TOXIN
• Organism(s): Vibrio cholerae O1
• Expression System: Vibrio natriegens
• Mutation(s): Yes 


• Deposited: 2023-08-11 Released: 2025-02-12 
• Deposition Author(s): Mojica, N., Cordara, G., Kersten, F., Heim, J.B., Krengel, U.
• Funding Organization(s): National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.60 Å
• R-Value Free: 
  0.222 (Depositor), 0.230 (DCC) 
• R-Value Work: 
  0.185 (Depositor), 0.194 (DCC) 

Starting Model: experimental

Literature

Cholera toxin variants

Kersten, F., Serrano, A., Mojica, N., Cordara, G., Heim, J.B., Tatulian, S.A., Krengel, U., Teter, K.

To be published.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 6-mer - A5B1 Local Symmetry: Cyclic - C5  (Explore in 3D)
Local Stoichiometry: Homo 5-mer - A5 

Local Symmetry: Cyclic - C5  (Explore in 3D)
Local Stoichiometry: Homo 5-mer - A5 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: gel filtration

Macromolecule Content 

• Total Structure Weight: 86.64 kDa 
• Atom Count: 6,874 
• Modeled Residue Count: 742 
• Deposited Residue Count: 755 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Cholera enterotoxin subunit A	A	240	Vibrio cholerae O1	Mutation(s): 1  Gene Names: ctxA, toxA, VC_1457
UniProt
Find proteins for P01555 (Vibrio cholerae serotype O1 (strain ATCC 39315 / El Tor Inaba N16961)) Explore P01555  Go to UniProtKB:  P01555

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Cholera enterotoxin subunit B	B [auth D], C [auth E], D [auth F], E [auth G], F [auth H]	103	Vibrio cholerae O1	Mutation(s): 2  Gene Names: ctxB, toxB, VC_1456
UniProt
Find proteins for P01556 (Vibrio cholerae serotype O1 (strain ATCC 39315 / El Tor Inaba N16961)) Explore P01556  Go to UniProtKB:  P01556

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
PEG	L [auth D], O [auth E]	DI(HYDROXYETHYL)ETHER C4 H10 O3 MTHSVFCYNBDYFN-UHFFFAOYSA-N
GOL	I [auth D], J [auth D], K [auth D], M [auth E], N [auth E], P [auth F], Q [auth G], R [auth G], S [auth G], T [auth H], U [auth H]	GLYCEROL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N
NA	G [auth A], H [auth A]	SODIUM ION Na FKNQFGJONOIPTF-UHFFFAOYSA-N

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
HIC	A	L-PEPTIDE LINKING	C7 H11 N3 O2		HIS

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.60 Å
• R-Value Free:  0.222 (Depositor), 0.230 (DCC) 
• R-Value Work:  0.185 (Depositor), 0.194 (DCC) 

Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 60.308	α = 90
b = 91.091	β = 106.403
c = 72.291	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
XDS	data scaling
PHASER	phasing
Coot	model building
MxCuBE	data collection
XDS	data reduction

Structure Validation

Entry History & Funding Information

Deposition Data

• Released Date: 2025-02-12 
Deposition Author(s): Mojica, N., Cordara, G., Kersten, F., Heim, J.B., Krengel, U.

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Funding Organization	Location	Grant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)	United States	R03AI112854
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)	United States	R01AI137056

Revision History  

• Version 1.0: 2025-02-12
  Type: Initial release