1LTB

2.6 ANGSTROMS CRYSTAL STRUCTURE OF PARTIALLY-ACTIVATED E. COLI HEAT-LABILE ENTEROTOXIN (LT)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Work: 0.172 
  • R-Value Observed: 0.172 

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This is version 1.2 of the entry. See complete history


Literature

Structure of partially-activated E. coli heat-labile enterotoxin (LT) at 2.6 A resolution.

Merritt, E.A.Pronk, S.E.Sixma, T.K.Kalk, K.H.van Zanten, B.A.Hol, W.G.

(1994) FEBS Lett 337: 88-92

  • DOI: 10.1016/0014-5793(94)80635-7
  • Primary Citation of Related Structures:  
    1LTB

  • PubMed Abstract: 
  • Biological toxicity of E. coli heat-labile enterotoxin and the closely related cholera toxin requires that the assembled toxin be activated by proteolytic cleavage of the A subunit and reduction of a disulfide bond internal to the A subunit. The structural role served by this reduction and cleavage is not known, however ...

    Biological toxicity of E. coli heat-labile enterotoxin and the closely related cholera toxin requires that the assembled toxin be activated by proteolytic cleavage of the A subunit and reduction of a disulfide bond internal to the A subunit. The structural role served by this reduction and cleavage is not known, however. We have crystallographically determined the structure of the E. coli heat-labile enterotoxin AB5 hexamer in which the A subunit has been cleaved by trypsin between residues 192 and 195. The toxin is thus partially activated, in that it has been cleaved but the disulfide bond has not been reduced. The structure of the A subunit in the cleaved toxin is substantially the same as that previously observed for the uncleaved AB5 structure, suggesting that although such cleavage is required for biological activity of the toxin it does not by itself cause a conformational change.


    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.M., Dauter, Z., Kingma, J., Witholt, B., Hol, W.G.J.
      (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.M., Witholt, B., Hol, W.G.J.
      (1991) Nature 351: 371

    Organizational Affiliation

    Department of Biological Structure SM-20, University of Washington, Seattle 98195.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
HEAT-LABILE ENTEROTOXIN, SUBUNIT BA [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)
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Go to UniProtKB:  P32890
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
HEAT-LABILE ENTEROTOXIN, SUBUNIT AF [auth A]185Escherichia coliMutation(s): 0 
Gene Names: eltAltpA
UniProt
Find proteins for P06717 (Escherichia coli)
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  • Reference Sequence
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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
HEAT-LABILE ENTEROTOXIN, SUBUNIT AG [auth C]45Escherichia coliMutation(s): 0 
Gene Names: eltAltpA
UniProt
Find proteins for P06717 (Escherichia coli)
Explore P06717 
Go to UniProtKB:  P06717
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Work: 0.172 
  • R-Value Observed: 0.172 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 119.2α = 90
b = 98.2β = 90
c = 64.8γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1994-01-31
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance