Cholera Toxin
What InterPro Tells Us
P01555 Vibrio cholerae enterotoxin A chain
InterPro Domain Architecture:
|
InterPro Entry |
Method Accession |
Graphical Match |
Method Name |
|
IPR001144 |
PF01375 |
|
Enterotoxin_a |
|
IPR001144 |
PR00771 |
|
ENTEROTOXINA |
|
Classification |
PDB Chain/ Domain ID |
PDB Chain/Structural Domains |
|
|
1s5d |
1s5dA |
|
|
|
3.90.210.10.1 |
1xtcA0 |
|
|
|
d.166.1.1 |
d1s5da_ |
|
|
From
the graphical match above, you can see that the signatures (method accession)
are grouped into one InterPro entry for Vibrio cholerae enterotoxin A
chain, namely IPR001144 representing the heat-labile
enterotoxin A chain family. IPR001144
has two signatures, PF01375 from the PFAM database, and PR00771 from the PRINTS database.
This entry groups together proteins related in sequence to enterotoxin A
chains from a variety of different toxins, several of which can be found in
different strains of Escherichia coli.
The remaining three entries in the table above are from the structural database PDB (green stripe), and from the structural classification databases CATH (pink stripe) and SCOP (black stripe) (the names such as d1s5da_ being derived from the PDB entry upon which it is based, here PDB entry 1s5d, chain A). The graphical match for the PDB entry 1s5d displays the length of the original PDB entry, which covers almost the entire protein. The CATH (1xtcA0) and SCOP (d1s5da_) databases give information on the classification of this protein.
P01556 Vibrio
cholerae enterotoxin B chain
InterPro Domain Architecture:
|
InterPro Entry |
Method Accession |
Graphical Match |
Method Name |
|
IPR001835 |
PD012805 |
|
Enterotoxin_B |
|
IPR001835 |
PF01376 |
|
Enterotoxin_b |
|
IPR001835 |
PR00772 |
|
ENTEROTOXINB |
|
IPR008992 |
SSF50203 |
|
Bact_endotox |
|
Classification |
PDB Chain/ Domain ID |
PDB Chain/Structural Domains |
|
|
3chb |
3chbD |
|
|
|
3chb |
3chbE |
|
|
|
3chb |
13chbF |
|
|
|
3chb |
3chbG |
|
|
|
3chb |
3chbH |
|
|
|
2.40.50.110.1 |
3chbD0 |
|
|
|
b.40.2.1 |
d3chbd_
|
|
|
From
the graphical match above, you can see that the signatures are divided into two
InterPro entries for Vibrio cholerae enterotoxin B chain. IPR001835 represents the heat-labile
enterotoxin B chain family, and has three signatures, PF01375 from the PFAM database, PR00772 from the PRINTS database, and PD012805 from the ProDom database.
This entry groups together proteins related in sequence to enterotoxin B
chains from a variety of different toxins, several of which can be found in
different strains of Escherichia coli. The
InterPro entry IPR008992 represents the bacterial enterotoxin
domain and has one signature, SSF50203 from the SUPERFAMILY database. IPR008992 groups together many proteins that
are structurally related to the cholera enterotoxin B chain, including E.
coli heat-labile protein, verotoxin-1, pertussis toxin, and several Staphylococcal
enterotoxins. Unlike the proteins making
up IPR001835, those in IPR008992 may have low sequence identities with one
another, but should still have a common evolutionary origin.
The graphical match for the PDB entry 1chb displays five chains that together represent the five identical peptides making up the cholera enterotoxin pentamer. The CATH (3chbD0) and SCOP (d3chbd_) databases give information on the classification of this protein.
What the Structure Tells Us
Structures
of the Vibrio cholerae enterotoxin A and B chains have been determined,
and can be viewed using AstexViewer®, which is linked from the InterPro Match
Table of each protein via the logo 
(please
note, there is no link directly from this page to the AstexViewer® for the
protein discussed above, therefore you need to go to the link on the InterPro
pages for P01555
or P10556). The AstexViewer® displays the PDB structure
with the particular CATH or SCOP domain highlighted in yellow. There are several structures associated cholera
toxin in the Protein Data Bank (PDB). A
detailed description and visualisation of the structural features of cholera
toxin can be found at the PDB ‘Molecule of the Month’,
providing insights into the molecular basis of action for this enterotoxin.