1LTB

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Work: 0.172 

wwPDB Validation 3D Report Full Report


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


  • 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 stru ...

    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: 
    • 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
    • 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


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HEAT-LABILE ENTEROTOXIN, SUBUNIT B
D, E, F, G, H
103Escherichia coliMutation(s): 0 
Gene Names: eltB (ltpB)
Find proteins for P32890 (Escherichia coli)
Go to UniProtKB:  P32890
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
HEAT-LABILE ENTEROTOXIN, SUBUNIT A
A
185Escherichia coliMutation(s): 0 
Gene Names: eltA (ltpA)
Find proteins for P06717 (Escherichia coli)
Go to UniProtKB:  P06717
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
HEAT-LABILE ENTEROTOXIN, SUBUNIT A
C
45Escherichia coliMutation(s): 0 
Gene Names: eltA (ltpA)
Find proteins for P06717 (Escherichia coli)
Go to UniProtKB:  P06717
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Work: 0.172 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 119.200α = 90.00
b = 98.200β = 90.00
c = 64.800γ = 90.00
Software Package:
Software NamePurpose
X-PLORphasing
X-PLORmodel building
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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