3HO6

Structure-function analysis of inositol hexakisphosphate-induced autoprocessing in clostridium difficile toxin A


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.198 
  • R-Value Work: 0.165 
  • R-Value Observed: 0.167 

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Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

Structure-function analysis of inositol hexakisphosphate-induced autoprocessing in Clostridium difficile toxin A.

Pruitt, R.N.Chagot, B.Cover, M.Chazin, W.J.Spiller, B.Lacy, D.B.

(2009) J Biol Chem 284: 21934-21940

  • DOI: https://doi.org/10.1074/jbc.M109.018929
  • Primary Citation of Related Structures:  
    3HO6

  • PubMed Abstract: 

    The action of Clostridium difficile toxins A and B depends on inactivation of host small G-proteins by glucosylation. Cellular inositol hexakisphosphate (InsP6) induces an autocatalytic cleavage of the toxins, releasing an N-terminal glucosyltransferase domain into the host cell cytosol. We have defined the cysteine protease domain (CPD) responsible for autoprocessing within toxin A (TcdA) and report the 1.6 A x-ray crystal structure of the domain bound to InsP6. InsP6 is bound in a highly basic pocket that is separated from an unusual active site by a beta-flap structure. Functional studies confirm an intramolecular mechanism of cleavage and highlight specific residues required for InsP6-induced TcdA processing. Analysis of the structural and functional data in the context of sequences from similar and diverse origins highlights a C-terminal extension and a pi-cation interaction within the beta-flap that appear to be unique among the large clostridial cytotoxins.


  • Organizational Affiliation

    Departments of Microbiology and Immunology, Nashville, Tennessee 37232.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Toxin A
A, B
267Clostridioides difficileMutation(s): 0 
Gene Names: tcdAtoxA
EC: 3.4.22
UniProt
Find proteins for P16154 (Clostridioides difficile)
Explore P16154 
Go to UniProtKB:  P16154
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP16154
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
IHP
Query on IHP

Download Ideal Coordinates CCD File 
C [auth A],
D [auth B]
INOSITOL HEXAKISPHOSPHATE
C6 H18 O24 P6
IMQLKJBTEOYOSI-GPIVLXJGSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.198 
  • R-Value Work: 0.165 
  • R-Value Observed: 0.167 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 141.312α = 90
b = 43.5β = 112.88
c = 94.692γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
SHARPphasing
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-06-23
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2020-10-14
    Changes: Derived calculations, Structure summary
  • Version 1.3: 2024-02-21
    Changes: Data collection, Database references