1CT1	Enterotoxin	date	Jun 03, 1997
title	Cholera Toxin B-Pentamer Mutant G33r Bound To Receptor 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 Mutation: G33r Biological_unit: Pentamer		Organism_scientific: Vibrio Cholerae Strain: Ogawa 41 (Classical Biotype) Expression_system: Escherichia Coli
symmetry	Space Group: C 1 2 1	R_factor	0.182
crystal cell	length a length b length c angle alpha angle beta angle gamma 103.400 67.610 101.700 90.00 131.66 90.00
method	X-Ray Diffraction	resolution	2.3 Å
ligand	CL, GAL, GLC, NGA, SIA	enzyme
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.
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] (107 Kb) [Save to disk] Biological Unit Coordinates (1ct1.pdb1.gz) 90 Kb CSU: Contacts of Structural Units for 1CT1 Likely Quarternary Molecular Structure file(s) for 1CT1 Structure Factors (219 Kb) Retrieve 1CT1 in mmCIF format [Save to disk]

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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 1CT1, from MSDmotif at EBI Genome occurence of 1CT1's fold from GeneCensus Classification of representative domains in scop (Structural Classification of Proteins)     - Domain d1ct1d_, region D [Jmol] [rasmolscript] [script source]     - Domain d1ct1e_, region E [Jmol] [rasmolscript] [script source]     - Domain d1ct1f_, region F [Jmol] [rasmolscript] [script source]     - Domain d1ct1g_, region G [Jmol] [rasmolscript] [script source]     - Domain d1ct1h_, region H [Jmol] [rasmolscript] [script source] Fold representative 1ct1 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: [1ct1_G] [1ct1_E] [1ct1_D] [1ct1_F] [1ct1_H]

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