1LT3

HEAT-LABILE ENTEROTOXIN DOUBLE MUTANT N40C/G166C


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.261 
  • R-Value Work: 0.188 
  • R-Value Observed: 0.188 

wwPDB Validation   3D Report Full Report


This is version 2.1 of the entry. See complete history


Literature

Crystal structure of heat-labile enterotoxin from Escherichia coli with increased thermostability introduced by an engineered disulfide bond in the A subunit.

van den Akker, F.Feil, I.K.Roach, C.Platas, A.A.Merritt, E.A.Hol, W.G.

(1997) Protein Sci 6: 2644-2649

  • DOI: 10.1002/pro.5560061219
  • Primary Citation of Related Structures:  
    1LT3

  • PubMed Abstract: 
  • Cholera toxin (CT) produced by Vibrio cholerae and heat-labile enterotoxin (LT-I), produced by enterotoxigenic Escherichia coli, are AB5 heterohexamers with an ADP-ribosylating A subunit and a GM1 receptor binding B pentamer. These toxins are among the most potent mucosal adjuvants known and, hence, are of interest both for the development of anti-diarrheal vaccines against cholera or enterotoxigenic Escherichia coli diarrhea and also for vaccines in general ...

    Cholera toxin (CT) produced by Vibrio cholerae and heat-labile enterotoxin (LT-I), produced by enterotoxigenic Escherichia coli, are AB5 heterohexamers with an ADP-ribosylating A subunit and a GM1 receptor binding B pentamer. These toxins are among the most potent mucosal adjuvants known and, hence, are of interest both for the development of anti-diarrheal vaccines against cholera or enterotoxigenic Escherichia coli diarrhea and also for vaccines in general. However, the A subunits of CT and LT-I are known to be relatively temperature sensitive. To improve the thermostability of LT-I an additional disulfide bond was introduced in the A1 subunit by means of the double mutation N40C and G166C. The crystal structure of this double mutant of LT-I has been determined to 2.0 A resolution. The protein structure of the N40C/G166C double mutant is very similar to the native structure except for a few local shifts near the new disulfide bond. The introduction of this additional disulfide bond increases the thermal stability of the A subunit of LT-I by 6 degrees C. The enhancement in thermostability could make this disulfide bond variant of LT-I of considerable interest for the design of enterotoxin-based vaccines.


    Related Citations: 
    • Refined Structure of Escherichia Coli Heat-Labile Enterotoxin, a Close Relative of Cholera Toxin
      Sixma, T.K., Kalk, K.H., Van Zanten, B.A., Dauter, Z., Kingma, J., Witholt, B., Hol, W.G.
      (1993) J Mol Biol 230: 890
    • Crystal Structure of a Cholera Toxin-Related Heat-Labile Enterotoxin from E. Coli
      Sixma, T.K., Pronk, S.E., Kalk, K.H., Wartna, E.S., Van Zanten, B.A., Witholt, B., Hol, W.G.
      (1991) Nature 351: 371

    Organizational Affiliation

    Department of Biochemistry, University of Washington, Seattle 98195-7420, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
HEAT-LABILE ENTEROTOXINA [auth D],
B [auth E],
C [auth F],
D [auth G],
E [auth H]
103Escherichia coliMutation(s): 0 
Gene Names: eltBltpB
UniProt
Find proteins for P32890 (Escherichia coli)
Explore P32890 
Go to UniProtKB:  P32890
Entity Groups  
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UniProt GroupP32890
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
HEAT-LABILE ENTEROTOXINF [auth A]240Escherichia coliMutation(s): 2 
Gene Names: eltAltpA
UniProt
Find proteins for P06717 (Escherichia coli)
Explore P06717 
Go to UniProtKB:  P06717
Entity Groups  
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UniProt GroupP06717
Protein Feature View
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 3
MoleculeChainsChain Length2D DiagramGlycosylation3D Interactions
beta-D-galactopyranose-(1-4)-beta-D-glucopyranoseG [auth B],
H [auth C],
I,
J,
K
2N/A Oligosaccharides Interaction
Glycosylation Resources
GlyTouCan:  G84224TW
GlyCosmos:  G84224TW
GlyGen:  G84224TW
Biologically Interesting Molecules (External Reference) 1 Unique
Entity ID: 3
IDChainsNameType/Class2D Diagram3D Interactions
PRD_900004
Query on PRD_900004
G [auth B], H [auth C], I, J, Kbeta-lactoseOligosaccharide / Nutrient Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.261 
  • R-Value Work: 0.188 
  • R-Value Observed: 0.188 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 119.7α = 90
b = 101.1β = 90
c = 64.2γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
X-PLORmodel building
X-PLORrefinement
X-PLORphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1997-07-07
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Structure summary
  • Version 2.1: 2021-11-03
    Changes: Database references, Structure summary