1LTA

2.2 ANGSTROMS CRYSTAL STRUCTURE OF E. COLI HEAT-LABILE ENTEROTOXIN (LT) WITH BOUND GALACTOSE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Work: 0.175 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Galactose-binding site in Escherichia coli heat-labile enterotoxin (LT) and cholera toxin (CT).

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

(1994) Mol.Microbiol. 13: 745-753


  • PubMed Abstract: 
  • The galactose-binding site in cholera toxin and the closely related heat-labile enterotoxin (LT) from Escherichia coli is an attractive target for the rational design of potential anti-cholera drugs. In this paper we analyse the molecular structure o ...

    The galactose-binding site in cholera toxin and the closely related heat-labile enterotoxin (LT) from Escherichia coli is an attractive target for the rational design of potential anti-cholera drugs. In this paper we analyse the molecular structure of this binding site as seen in several crystal structures, including that of an LT:galactose complex which we report here at 2.2 A resolution. The binding surface on the free toxin contains several tightly associated water molecules and a relatively flexible loop consisting of residues 51-60 of the B subunit. During receptor binding this loop becomes tightly ordered by forming hydrogen bonds jointly to the GM1 pentasaccharide and to a set of water molecules which stabilize the toxin:receptor complex.


    Related Citations: 
    • Lactose Binding to Heat-Labile Enterotoxin Revealed by X-Ray Crystallography
      Sixma, T.K.,Pronk, S.E.,Kalk, K.H.,Van Zanten, B.A.M.,Berghuis, A.M.,Hol, W.G.J.
      (1992) Nature 355: 561
    • 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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HEAT-LABILE ENTEROTOXIN, SUBUNIT B
D, E, F, G, H
103Escherichia coliGene Names: eltB (ltpB)
Find proteins for P32890 (Escherichia coli)
Go to UniProtKB:  P32890
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
HEAT-LABILE ENTEROTOXIN, SUBUNIT A
A
188Escherichia coliGene Names: eltA (ltpA)
Find proteins for P06717 (Escherichia coli)
Go to UniProtKB:  P06717
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
HEAT-LABILE ENTEROTOXIN, SUBUNIT A
C
49Escherichia coliGene Names: eltA (ltpA)
Find proteins for P06717 (Escherichia coli)
Go to UniProtKB:  P06717
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GAL
Query on GAL

Download SDF File 
Download CCD File 
D, E, F, G, H
BETA-D-GALACTOSE
C6 H12 O6
WQZGKKKJIJFFOK-FPRJBGLDSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Work: 0.175 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 70.700α = 90.00
b = 73.500β = 90.00
c = 163.300γ = 90.00
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORphasing
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