1LT4

HEAT-LABILE ENTEROTOXIN MUTANT S63K


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.192 
  • R-Value Observed: 0.192 

wwPDB Validation   3D Report Full Report


This is version 2.1 of the entry. See complete history


Literature

Crystal structure of a non-toxic mutant of heat-labile enterotoxin, which is a potent mucosal adjuvant.

van den Akker, F.Pizza, M.Rappuoli, R.Hol, W.G.

(1997) Protein Sci 6: 2650-2654

  • DOI: 10.1002/pro.5560061220
  • Primary Citation of Related Structures:  
    1LT4

  • PubMed Abstract: 
  • Two closely related bacterial toxins, heat-labile enterotoxin (LT-I) and cholera toxin (CT), not only invoke a toxic activity that affects many victims worldwide but also contain a beneficial mucosal adjuvant activity that significantly enhances the potency of vaccines in general ...

    Two closely related bacterial toxins, heat-labile enterotoxin (LT-I) and cholera toxin (CT), not only invoke a toxic activity that affects many victims worldwide but also contain a beneficial mucosal adjuvant activity that significantly enhances the potency of vaccines in general. For the purpose of vaccine design it is most interesting that the undesirable toxic activity of these toxins can be eliminated by the single-site mutation Ser63Lys in the A subunit while the mucosal adjuvant activity is still present. The crystal structure of the Ser63Lys mutant of LT-I is determined at 2.0 A resolution. Its structure appears to be essentially the same as the wild-type LT-I structure. The substitution Ser63Lys was designed, based on the wild-type LT-I crystal structure, to decrease toxicity by interfering with NAD binding and/or catalysis. In the mutant crystal structure, the newly introduced lysine side chain is indeed positioned such that it could potentially obstruct the productive binding mode of the substrate NAD while at the same time its positive charge could possibly interfere with the critical function of nearby charged groups in the active site of LT-I. The fact that the Ser63Lys mutant of LT-I does not disrupt the wild-type LT-I structure makes the non-toxic mutant potentially suitable, from a structural point of view, to be used as a vaccine to prevent enterotoxigenic E. coli infections. The structural similarity of mutant and wild-type toxin might also be the reason why the inactive Ser63Lys variant retains its adjuvant activity.


    Related Citations: 
    • Probing the Structure-Activity Relationship of Escherichia Coli Lt-A by Site-Directed Mutagenesis
      Pizza, M., Domenighini, M., Hol, W., Giannelli, V., Fontana, M.R., Giuliani, M.M., Magagnoli, C., Peppoloni, S., Manetti, R., Rappuoli, R.
      (1994) Mol Microbiol 14: 51
    • 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  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
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]247Escherichia coliMutation(s): 1 
UniProt
Find proteins for Q2HQJ7 (Musa acuminata)
Explore Q2HQJ7 
Go to UniProtKB:  Q2HQJ7
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UniProt GroupQ2HQJ7
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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: 0.255 
  • R-Value Work: 0.192 
  • R-Value Observed: 0.192 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 120α = 90
b = 101.9β = 90
c = 64.4γ = 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: 1997-06-16
    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, Database references, Derived calculations, Structure summary
  • Version 2.1: 2021-11-03
    Changes: Database references, Structure summary