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 Diffraction	resolution	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	Chain Function Process Component H, F, D, G, E pathogenesis extracellular region membrane
Primary reference	Structural 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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Visual 3D analysis of 2CHB

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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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