2CHB Toxin date Jun 03, 1997
title Cholera Toxin B-Pentamer Complexed With Gm1 Pentasaccharide
authors E.A.Merritt, W.G.J.Hol
compound source
Molecule: Cholera Toxin
Chain: D, E, F, G, H
Fragment: B-Pentamer
Engineered: Yes
Biological_unit: Pentamer
Other_details: Receptor Binding Site On Each Monomer Occupied By Gm1 Pentasaccharide
 Organism_scientific: Vibrio Cholerae
Strain: Ogawa 41 (Classical Biotype)
Expression_system: Escherichia Coli
symmetry Space Group: C 1 2 1
R_factor 0.171
crystal
cell
length a length b length c angle alpha angle beta angle gamma
101.900 67.580 80.470 90.00 105.69 90.00
method X-Ray Diffractionresolution 2.0 Å
ligand GAL, GLC, NGA, SIA enzyme
note 2CHB supersedes 1CHB
similarity Belongs to the Enterotoxin_b family.
subunit The a subunit contains two chains, a1 and a2, linked by a disulfide bridge. The holotoxin (choleragen) consists of a pentameric ring of b subunits whose central pore is occupied by the a subunit.
gene ctxB (V. cholerae)
function It can bind five gm1 gangliosides. The b subunit pentameric ring directs the a subunit to its target by binding to the gm1 gangliosides present on the surface of the intestinal epithelial cells. It has no toxic activity by itself.
Gene
Ontology
ChainFunctionProcessComponent
H, F, D, G, E
  • pathogenesis
  • extracellular region
  • membrane
    • Primary referenceStructural studies of receptor binding by cholera toxin mutants., Merritt EA, Sarfaty S, Jobling MG, Chang T, Holmes RK, Hirst TR, Hol WG, Protein Sci 1997 Jul;6(7):1516-28. PMID:9232653
    Data retrieval
  • Asymmetric unit, PDB entry: [header only] [complete with coordinates] (114 Kb) [Save to disk]
  • Biological Unit Coordinates (2chb.pdb1.gz) 99 Kb
  • CSU: Contacts of Structural Units for 2CHB
  • Likely Quarternary Molecular Structure file(s) for 2CHB
  • Structure Factors (394 Kb)
  • Retrieve 2CHB in mmCIF format [Save to disk]
    • View 2CHB in 3D
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    • Structure-derived information
  • Electron Density related parameters from EDS Electron Density Server, at Upsala
  • Dipole moment, from Dipole Server at Weizmann Institute
  • Crystal Contacts, from CryCo at Weizmann Institute
  • 3D motif for 2CHB, from MSDmotif at EBI
  • Genome occurence of 2CHB's fold from GeneCensus
  • Classification of representative domains in scop (Structural Classification of Proteins)
        - Domain d2chbd_, region D [Jmol] [rasmolscript] [script source]
        - Domain d2chbe_, region E [Jmol] [rasmolscript] [script source]
        - Domain d2chbf_, region F [Jmol] [rasmolscript] [script source]
        - Domain d2chbg_, region G [Jmol] [rasmolscript] [script source]
        - Domain d2chbh_, region H [Jmol] [rasmolscript] [script source]
  • Fold representative 2chb from FSSP and Dali (Families of Structurally Similar Proteins)
  • Class (fold), Architecture (subfold), Topology, Homologous superfamily from CATH
  • Summaries and structural analyses of PDB data files from PDBSum
  • Identification of Protein Pockets & Cavities at CASTp
    • Sequence-derived information
  • View one-letter amino acid or nucleotide sequence for each chain: [2chb_D] [2chb_G] [2chb_E] [2chb_H] [2chb_F]
    • Other resources with information on 2CHB
  • InterPro: IPR001835
  • PDBREPORT (protein verification by WHAT_CHECK procedures)
  • MMDB (Entrez's Structure Database)
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