P06717 (ELAP_ECOLX) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Heat-labile enterotoxin A chain

Alternative name(s):
LT-A, porcine
LTP-A

Gene names

Name:	eltA
Synonyms:	ltpA

Organism

Escherichia coli

Taxonomic identifier

562 [NCBI]

Taxonomic lineage

cellular organisms › Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacteriales › Enterobacteriaceae › Escherichia

Protein attributes

Sequence length	258 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 biological activity of the toxin is produced by the A chain, which activates intracellular adenyl cyclase.
Subunit structure	Heterohexamer of one A chain and of five B chains.
Sequence similarities	Belongs to the enterotoxin A family.

Ontologies

Keywords
Domain	Signal
Molecular function	Enterotoxin Toxin
PTM	Disulfide bond
Technical term	3D-structure
Gene Ontology (GO)
Biological_process	metabolic process Inferred from electronic annotation. Source: GOC pathogenesis Inferred from electronic annotation. Source: UniProtKB-KW
Cellular_component	extracellular region Inferred from electronic annotation. Source: InterPro
Molecular_function	catalytic activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Signal peptide

1 – 18

18

Chain

19 – 258

240

Heat-labile enterotoxin A chain

PRO_0000019351

Regions

Nucleotide binding

25 – 39

15

NAD

Sites

Active site

130

1

Amino acid modifications

Disulfide bond

205 ↔ 217

Natural variations

Natural variant

130

1

E → K in inactive mutant.

Experimental info

Mutagenesis

25

1

R → K: Abolishes toxicity. Ref.8

Mutagenesis

71

1

V → D or E: Abolishes toxicity. Ref.8

Mutagenesis

72

1

R → A or K: No effect. Ref.8

Mutagenesis

77

1

Y → M: No effect. Ref.8

Mutagenesis

81

1

S → K: Abolishes toxicity. Ref.8

Mutagenesis

90

1

A → E, H or R: No effect. Ref.8

Mutagenesis

115

1

V → K: Abolishes toxicity. Ref.8

Mutagenesis

122

1

Y → D or K: Abolishes toxicity. Ref.8

Mutagenesis

125

1

H → E: Strongly reduces toxicity. Ref.8

Mutagenesis

128

1

E → S: Abolishes toxicity. Ref.8

Mutagenesis

130

1

E → S: Abolishes toxicity. Ref.8

Mutagenesis

132

1

S → E or K: Abolishes toxicity. Ref.8

Mutagenesis

210

1

R → N: No effect. Ref.8

Sequence conflict

37 – 39

3

SGG → FRS in CAA23532. Ref.3

Sequence conflict

45

1

Missing in CAA23532. Ref.3

Sequence conflict

93

1

S → Y in CAA23532. Ref.3

Sequence conflict

100 – 110

11

TYYIYVIATAP → LTIYIVIA in CAA23532. Ref.3

Sequence conflict

119 – 120

2

LG → IS in CAA23532. Ref.3

Sequence conflict

159

1

R → G in AAB59161. Ref.4

Sequence conflict

207

1

N → D in CAA23532. Ref.3

Secondary structure

1

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258

Helix Strand Turn

Details...

Beta strand

23 – 29

7

Helix

31 – 37

7

Helix

59 – 64

6

Beta strand

70 – 72

3

Beta strand

75 – 83

9

Helix

84 – 94

11

Beta strand

99 – 106

8

Beta strand

112 – 114

3

Helix

115 – 119

5

Helix

120 – 122

3

Helix

126 – 128

3

Beta strand

130 – 134

5

Helix

139 – 141

3

Beta strand

142 – 149

8

Beta strand

152 – 159

8

Helix

165 – 168

4

Helix

176 – 178

3

Helix

180 – 182

3

Helix

190 – 193

4

Helix

197 – 200

4

Helix

215 – 240

26

Helix

241 – 244

4

Helix

250 – 253

4

Sequences

	Sequence		Length	Mass (Da)
	P06717 [UniParc]. Last modified January 1, 1988. Version 1. Checksum: 2F0786442619F81F	FASTA	258	29,902
	10 20 30 40 50 60 MKNITFIFFI LLASPLYANG DRLYRADSRP PDEIKRSGGL MPRGHNEYFD RGTQMNINLY 70 80 90 100 110 120 DHARGTQTGF VRYDDGYVST SLSLRSAHLA GQSILSGYST YYIYVIATAP NMFNVNDVLG 130 140 150 160 170 180 VYSPHPYEQE VSALGGIPYS QIYGWYRVNF GVIDERLHRN REYRDRYYRN LNIAPAEDGY 190 200 210 220 230 240 RLAGFPPDHQ AWREEPWIHH APQGCGNSSR TITGDTCNEE TQNLSTIYLR EYQSKVKRQI 250 FSDYQSEVDI YNRIRDEL

References

[1]	"Evolutionary origin of pathogenic determinants in enterotoxigenic Escherichia coli and Vibrio cholerae O1." Yamamoto T., Gojobori T., Yokota T. J. Bacteriol. 169:1352-1357(1987) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: Isolate P307 / ETEC and Isolate PCG86 / ETEC.
[2]	"A comparison of the nucleotide sequence of the A subunit of heat-labile enterotoxin and cholera toxin." Dykes C.W., Halliday I.J., Hobden A.N., Read M.J., Harford S. FEMS Microbiol. Lett. 26:171-174(1985) Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: Isolate P307 / ETEC.
[3]	"Escherichia coli heat-labile enterotoxin. Nucleotide sequence of the A subunit gene." Spicer E.K., Noble J.A. J. Biol. Chem. 257:5716-5721(1982) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: Isolate P307 / ETEC.
[4]	"A single amino acid substitution in the A subunit of Escherichia coli enterotoxin results in a loss of its toxic activity." Tsuji T., Inoue T., Miyama A., Okamoto K., Honda T., Miwatani T. J. Biol. Chem. 265:22520-22525(1990) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 19-258. Strain: Isolate P307 / ETEC.
[5]	Trachman J.D., Maas W.K. Submitted (JUL-1991) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-40.
[6]	"Crystal structure of a cholera toxin-related heat-labile enterotoxin from E. coli." Sixma T.K., Pronk S.E., Kalk K.H., Wartna E.S., van Zanten B.A.M., Witholt B., Hol W.G.J. Nature 351:371-377(1991) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.3 ANGSTROMS).
[7]	"Refined structure of Escherichia coli heat-labile enterotoxin, a close relative of cholera toxin." Sixma T.K., van Zanten B.A.M., Dauter Z., Hol W.G.J. J. Mol. Biol. 230:890-918(1993) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.95 ANGSTROMS).
[8]	"Probing the structure-activity relationship of Escherichia coli LT-A by site-directed mutagenesis." Pizza M., Domenighini M., Hol W.G.J., Giannelli V., Fontana M.R., Giuliani M.M., Magagnoli C., Peppoloni S., Manetti R., Rappuoli R. Mol. Microbiol. 14:51-60(1994) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.4 ANGSTROMS) OF 19-258, MUTAGENESIS OF ARG-25; VAL-71; ARG-72; TYR-77; SER-81; ALA-90; VAL-115; TYR-122; HIS-125; GLU-128; GLU-130; SER-132 AND ARG-210.
[9]	"Identification of errors among database sequence entries and comparison of correct amino acid sequences for the heat-labile enterotoxins of Escherichia coli and Vibrio cholerae." Domenighini M., Pizza M., Jobling M.G., Holmes R.K., Rappuoli R. Mol. Microbiol. 15:1165-1167(1995) [PubMed] [Europe PMC] [Abstract] Cited for: DISCUSSION OF SEQUENCE.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

M15361 Genomic DNA. Translation: AAA24791.1.
M15362 Genomic DNA. Translation: AAA24793.1.
M35581 Genomic DNA. Translation: AAA98202.1.
V00275 Genomic DNA. Translation: CAA23532.1.
M57244 Genomic DNA. Translation: AAB59161.1.
M61015 Genomic DNA. Translation: AAA24335.1.

PIR

QLECA. I55231.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1HTL	X-ray	2.50	A	19-209	[»]
			C	210-258	[»]
1LT3	X-ray	2.00	A	19-258	[»]
1LT4	X-ray	2.00	A	19-251	[»]
1LTA	X-ray	2.20	A	19-206	[»]
			C	210-258	[»]
1LTB	X-ray	2.60	A	22-206	[»]
			C	210-254	[»]
1LTG	X-ray	2.40	A	19-209	[»]
			C	210-258	[»]
1LTI	X-ray	2.13	A	19-210	[»]
			C	211-258	[»]
1LTS	X-ray	1.95	A	22-206	[»]
			C	214-254	[»]
1LTT	X-ray	2.30	A	22-206	[»]
			C	214-254	[»]

ProteinModelPortal

P06717.

SMR

P06717. Positions 19-258.

ModBase

Search...

Protein-protein interaction databases

IntAct

P06717. 1 interaction.

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Family and domain databases

InterPro

IPR001144. Enterotoxin_A.
[Graphical view]

Pfam

PF01375. Enterotoxin_a. 1 hit.
[Graphical view]

PRINTS

PR00771. ENTEROTOXINA.

ProtoNet

Search...

Other

EvolutionaryTrace

P06717.

Entry information

Entry name

ELAP_ECOLX

Accession

Primary (citable) accession number: P06717
Secondary accession number(s): P01554

Entry history

Integrated into UniProtKB/Swiss-Prot:	January 1, 1988
Last sequence update:	January 1, 1988
Last modified:	April 3, 2013
This is version 80 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program