P01556 (CHTB_VIBCH) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Cholera enterotoxin subunit B

Alternative name(s):
Cholera enterotoxin B chain
Cholera enterotoxin gamma chain
Choleragenoid

Gene names

Name:	ctxB
Synonyms:	toxB
Ordered Locus Names:	VC_1456

Organism

Vibrio cholerae serotype O1 (strain ATCC 39315 / El Tor Inaba N16961) [Reference proteome] [HAMAP]

Taxonomic identifier

243277 [NCBI]

Taxonomic lineage

cellular organisms › Bacteria › Proteobacteria › Gammaproteobacteria › Vibrionales › Vibrionaceae › Vibrio › Vibrio cholerae › Vibrio cholerae O1 › Vibrio cholerae O1 biovar El Tor

Protein attributes

Sequence length	124 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	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 can bind five GM1 gangliosides. It has no toxic activity by itself.
Subunit structure	The holotoxin (choleragen) consists of a pentameric ring of B subunits whose central pore is occupied by the A subunit. The A subunit contains two chains, A1 and A2, linked by a disulfide bridge. Ref.9
Subcellular location	Secreted. Host cell membrane Potential.

Ontologies

Keywords
Cellular component	Host cell membrane Host membrane Membrane Secreted
Domain	Signal
Molecular function	Enterotoxin Toxin
PTM	Disulfide bond
Technical term	3D-structure Complete proteome Direct protein sequencing Reference proteome
Gene Ontology (GO)
Biological_process	killing of cells of other organism Inferred from mutant phenotype Ref.2. Source: TIGR pathogenesis Inferred from mutant phenotype Ref.2. Source: TIGR protein ADP-ribosylation Inferred from mutant phenotype Ref.2. Source: TIGR
Cellular_component	host cell plasma membrane Inferred from electronic annotation. Source: UniProtKB-SubCell membrane Inferred from electronic annotation. Source: UniProtKB-KW
Molecular_function	host cell surface binding Inferred from direct assay Ref.13. Source: TIGR
Complete GO annotation...

Binary interactions

With	Entry	#Exp.	IntAct	Notes
ctxA	P01555	5	EBI-1038383,EBI-1038392

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Signal peptide

1 – 21

21

Ref.7 Ref.8

Chain

22 – 124

103

Cholera enterotoxin subunit B

PRO_0000019344

Amino acid modifications

Disulfide bond

30 ↔ 107

Ref.7

Experimental info

Mutagenesis

78

1

H → A: Loss of toxicity.

Sequence conflict

33

1

Y → S in CAA24996. Ref.2

Sequence conflict

39

1

Y → H AA sequence Ref.7

Sequence conflict

39

1

Y → H AA sequence Ref.8

Sequence conflict

43

1

D → N AA sequence Ref.7

Sequence conflict

43

1

D → N AA sequence Ref.8

Sequence conflict

68

1

I → T AA sequence Ref.7

Sequence conflict

68

1

I → T AA sequence Ref.8

Sequence conflict

70

1

Q → E AA sequence Ref.8

Sequence conflict

75

1

G → S in CAA24996. Ref.2

Sequence conflict

91

1

D → N AA sequence Ref.7

Sequence conflict

91

1

D → N AA sequence Ref.8

Secondary structure

1

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

124

Helix Strand Turn

Details...

Helix

26 – 30

5

Beta strand

36 – 43

8

Beta strand

46 – 51

6

Beta strand

58 – 62

5

Beta strand

68 – 71

4

Helix

82 – 99

18

Beta strand

103 – 109

7

Beta strand

112 – 123

12

Sequences

	Sequence		Length	Mass (Da)
	P01556 [UniParc]. Last modified August 13, 1987. Version 1. Checksum: 9AA393E3EA8E3EBF	FASTA	124	13,957
	10 20 30 40 50 60 MIKLKFGVFF TVLLSSAYAH GTPQNITDLC AEYHNTQIYT LNDKIFSYTE SLAGKREMAI 70 80 90 100 110 120 ITFKNGAIFQ VEVPGSQHID SQKKAIERMK DTLRIAYLTE AKVEKLCVWN NKTPHAIAAI SMAN

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Nucleotide sequence analysis of the A2 and B subunits of Vibrio cholerae enterotoxin." Lockman H., Kaper J.B. J. Biol. Chem. 258:13722-13726(1983) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[2]	"Cholera toxin genes: nucleotide sequence, deletion analysis and vaccine development." Mekalanos J.J., Swartz D.J., Pearson G.D.N., Harford N., Groyne F., de Wilde M. Nature 306:551-557(1983) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: ATCC 39050 / El Tor Inaba 2125 / Serotype O1.
[3]	"Structure and arrangement of the cholera toxin genes in Vibrio cholerae O139." Lebens M., Holmgren J. FEMS Microbiol. Lett. 117:197-202(1994) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: 4260B / Serotype O139.
[4]	Dams E., de Wolf M., Dierick W. Submitted (MAY-1991) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: ATCC 39050 / El Tor Inaba 2125 / Serotype O1.
[5]	Yamamoto K., Do V.G.R.F., Xu M., Iida T., Miwatani T., Albert M.J., Honda T. Submitted (MAY-1994) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: 1854 / O139-Bengal.
[6]	"DNA sequence of both chromosomes of the cholera pathogen Vibrio cholerae." Heidelberg J.F., Eisen J.A., Nelson W.C., Clayton R.A., Gwinn M.L., Dodson R.J., Haft D.H., Hickey E.K., Peterson J.D., Umayam L.A., Gill S.R., Nelson K.E., Read T.D., Tettelin H., Richardson D.L., Ermolaeva M.D., Vamathevan J.J., Bass S. , Qin H., Dragoi I., Sellers P., McDonald L.A., Utterback T.R., Fleischmann R.D., Nierman W.C., White O., Salzberg S.L., Smith H.O., Colwell R.R., Mekalanos J.J., Venter J.C., Fraser C.M. Nature 406:477-483(2000) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: ATCC 39315 / El Tor Inaba N16961.
[7]	"Covalent structure of the beta chain of cholera enterotoxin." Kurosky A., Markel D.E., Peterson J.W. J. Biol. Chem. 252:7257-7264(1977) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 22-124.
[8]	"Determination of the primary structure of cholera toxin B subunit." Lai C.-Y. J. Biol. Chem. 252:7249-7256(1977) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 22-124.
[9]	"The arrangement of subunits in cholera toxin." Gill D.M. Biochemistry 15:1242-1248(1976) [PubMed] [Europe PMC] [Abstract] Cited for: SUBUNIT.
[10]	"Gangliosides that associate with lipid rafts mediate transport of cholera and related toxins from the plasma membrane to endoplasmic reticulm." Fujinaga Y., Wolf A.A., Rodighiero C., Wheeler H., Tsai B., Allen L., Jobling M.G., Rapoport T., Holmes R.K., Lencer W.I. Mol. Biol. Cell 14:4783-4793(2003) [PubMed] [Europe PMC] [Abstract] Cited for: TRANSPORT OF CHOLERA TOXIN WITHIN THE INTESTINAL CELL.
[11]	"Crystal structure of cholera toxin B-pentamer bound to receptor GM1 pentasaccharide." Merritt E.A., Sarfaty S., van den Akker F., L'Hoir C., Martial J.A., Hol W.G.J. Protein Sci. 3:166-175(1994) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.2 ANGSTROMS).
[12]	"The 2.4 A crystal structure of cholera toxin B subunit pentamer: choleragenoid." Zhang R.-G., Westbrook M.L., Westbrook E.M., Scott D.L., Otwinowski Z., Maulik P.R., Reed R.A., Shipley G.G. J. Mol. Biol. 251:550-562(1995) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.4 ANGSTROMS).
[13]	"Structural studies of receptor binding by cholera toxin mutants." Merritt E.A., Sarfaty S., Jobling M.G., Chang T., Holmes R.K., Hirst T.R., Hol W.G.J. Protein Sci. 6:1516-1528(1997) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.25 ANGSTROMS). Strain: Ogawa 41 / Classical biotype.
[14]	"A mutant cholera toxin B subunit that binds GM1-ganglioside but lacks immunomodulatory or toxic activity." Aman A.T., Fraser S., Merritt E.A., Rodigherio C., Kenny M., Ahn M., Hol W.G.J., Williams N.A., Lencer W.I., Hirst T.R. Proc. Natl. Acad. Sci. U.S.A. 98:8536-8541(2001) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS) OF MUTANT ALA-57.
[15]	"Anchor-based design of improved cholera toxin and E. coli heat-labile enterotoxin receptor binding antagonists that display multiple binding modes." Pickens J.C., Merritt E.A., Ahn M., Verlinde C.L.M.J., Hol W.G.J., Fan E. Chem. Biol. 9:215-224(2002) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.3 ANGSTROMS) IN COMPLEX WITH INHIBITOR.
[16]	"Solution and crystallographic studies of branched multivalent ligands that inhibit the receptor-binding of cholera toxin." Zhang Z., Merritt E.A., Ahn M., Roach C., Hou Z., Verlinde C.L.M.J., Hol W.G.J., Fan E. J. Am. Chem. Soc. 124:12991-12998(2002) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.45 ANGSTROMS).
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

K01170 Genomic DNA. Translation: AAA27573.1.
X00171 Genomic DNA. Translation: CAA24996.1.
X76390 Genomic DNA. Translation: CAA53973.1.
X76391 Genomic DNA. Translation: CAA53976.1.
X58786 Genomic DNA. Translation: CAA41593.1.
D30053 Genomic DNA. Translation: BAA06291.1.
AE003852 Genomic DNA. Translation: AAF94613.1.

PIR

XVVCB. S14624.

RefSeq

NP_231099.1. NC_002505.1.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1CHP	X-ray	2.00	D/E/F/G/H	22-124	[»]
1CHQ	X-ray	2.10	D/E/F/G/H	22-124	[»]
1CT1	X-ray	2.30	D/E/F/G/H	22-124	[»]
1FGB	X-ray	2.40	D/E/F/G/H	22-124	[»]
1G8Z	X-ray	2.00	D/E/F/G/H	22-124	[»]
1JR0	X-ray	1.30	D/E/F/G/H	22-124	[»]
1MD2	X-ray	1.45	D/E/F/G/H	22-124	[»]
1RCV	X-ray	1.60	D/E/F/G/H	22-124	[»]
1RD9	X-ray	1.44	D/E/F/G/H	22-124	[»]
1RDP	X-ray	1.35	D/E/F/G/H	22-124	[»]
1RF2	X-ray	1.35	D/E/F/G/H	22-124	[»]
1S5B	X-ray	2.13	D/E/F/G/H	22-124	[»]
1S5C	X-ray	2.50	D/E/F/G/H	22-124	[»]
1S5D	X-ray	1.75	D/E/F/G/H	22-124	[»]
1S5E	X-ray	1.90	D/E/F/G/H/J/K/L/M/N	22-124	[»]
1S5F	X-ray	2.60	D/E/F/G/H	22-124	[»]
1XTC	X-ray	2.40	D/E/F/G/H	22-124	[»]
2CHB	X-ray	2.00	D/E/F/G/H	22-124	[»]
3CHB	X-ray	1.25	D/E/F/G/H	22-124	[»]
3EFX	X-ray	1.94	D/E/F/G/H/I/J/K/L/M	23-124	[»]

ProteinModelPortal

P01556.

ModBase

Search...

Protein-protein interaction databases

DIP

DIP-6256N.

IntAct

P01556. 1 interaction.

MINT

MINT-7040506.

STRING

243277.VC1456.

Protocols and materials databases

DNASU

2613962.

StructuralBiologyKnowledgebase

Search...

Genome annotation databases

EnsemblBacteria

AAF94613; AAF94613; VC_1456.

GeneID

2613962.

KEGG

vch:VC1456.

PATRIC

20081974. VBIVibCho83274_1386.

Phylogenomic databases

KO

K10929.

OMA

GKREMAI.

ProtClustDB

CLSK2484299.

Family and domain databases

InterPro

IPR001835. Enterotoxin_B.
IPR008992. Enterotoxin_bac.
[Graphical view]

Pfam

PF01376. Enterotoxin_b. 1 hit.
[Graphical view]

PRINTS

PR00772. ENTEROTOXINB.

ProDom

PD012805. Enterotoxin_B. 1 hit.
[Graphical view] [Entries sharing at least one domain]

SUPFAM

SSF50203. Bact_endotox. 1 hit.

ProtoNet

Search...

Other

EvolutionaryTrace

P01556.

Entry information

Entry name

CHTB_VIBCH

Accession

Primary (citable) accession number: P01556
Secondary accession number(s): Q9JQ02

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 21, 1986
Last sequence update:	August 13, 1987
Last modified:	May 29, 2013
This is version 109 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program