4FO2

Heat-labile enterotoxin LT-IIb-B5(T13I) mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.5 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.223 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structure-activity correlations of variant forms of the B pentamer of Escherichia coli type II heat-labile enterotoxin LT-IIb with Toll-like receptor 2 binding.

Cody, V.Pace, J.Nawar, H.F.King-Lyons, N.Liang, S.Connell, T.D.Hajishengallis, G.

(2012) Acta Crystallogr.,Sect.D 68: 1604-1612

  • DOI: 10.1107/S0907444912038917
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The pentameric B subunit of the type II heat-labile enterotoxin of Escherichia coli (LT-IIb-B(5)) is a potent signaling molecule capable of modulating innate immune responses. It has previously been shown that LT-IIb-B(5), but not the LT-IIb-B(5) Ser ...

    The pentameric B subunit of the type II heat-labile enterotoxin of Escherichia coli (LT-IIb-B(5)) is a potent signaling molecule capable of modulating innate immune responses. It has previously been shown that LT-IIb-B(5), but not the LT-IIb-B(5) Ser74Asp variant [LT-IIb-B(5)(S74D)], activates Toll-like receptor (TLR2) signaling in macrophages. Consistent with this, the LT-IIb-B(5)(S74D) variant failed to bind TLR2, in contrast to LT-IIb-B(5) and the LT-IIb-B(5) Thr13Ile [LT-IIb-B(5)(T13I)] and LT-IIb-B(5) Ser74Ala [LT-IIb-B(5)(S74A)] variants, which displayed the highest binding activity to TLR2. Crystal structures of the Ser74Asp, Ser74Ala and Thr13Ile variants of LT-IIb-B(5) have been determined to 1.90, 1.40 and 1.90 Å resolution, respectively. The structural data for the Ser74Asp variant reveal that the carboxylate side chain points into the pore, thereby reducing the pore size compared with that of the wild-type or the Ser74Ala variant B pentamer. On the basis of these crystallographic data, the reduced TLR2-binding affinity of the LT-IIb-B(5)(S74D) variant may be the result of the pore of the pentamer being closed. On the other hand, the explanation for the enhanced TLR2-binding activity of the LT-IIb-B(5)(S74A) variant is more complex as its activity is greater than that of the wild-type B pentamer, which also has an open pore as the Ser74 side chain points away from the pore opening. Data for the LT-IIb-B(5)(T13I) variant show that four of the five variant side chains point to the outside surface of the pentamer and one residue points inside. These data are consistent with the lack of binding of the LT-IIb-B(5)(T13I) variant to GD1a ganglioside.


    Organizational Affiliation

    Structural Biology Department, Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA. cody@hwi.buffalo.edu




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Heat-labile enterotoxin IIB, B chain
D, E, F, G, H, A, B, C, I, J, K, L, M, N, O, P, Q, R, S, T
98Escherichia coliMutation(s): 1 
Find proteins for P43529 (Escherichia coli)
Go to UniProtKB:  P43529
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

Download SDF File 
Download CCD File 
B, C, E, F, L, M, Q, R
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
ACT
Query on ACT

Download SDF File 
Download CCD File 
N, Q
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.5 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.223 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 119.310α = 90.00
b = 119.976β = 90.05
c = 142.446γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data collection
SCALAdata scaling
MOLREPphasing
REFMACrefinement
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-11-21
    Type: Initial release
  • Version 1.1: 2012-11-28
    Type: Database references