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| | <StructureSection load='1xtc' size='340' side='right'caption='[[1xtc]], [[Resolution|resolution]] 2.40Å' scene=''> | | <StructureSection load='1xtc' size='340' side='right'caption='[[1xtc]], [[Resolution|resolution]] 2.40Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1xtc]] is a 7 chain structure with sequence from [https://en.wikipedia.org/wiki/Vibrio_cholerae Vibrio cholerae]. The September 2005 RCSB PDB [https://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Cholera Toxin'' by David S. Goodsell is [https://dx.doi.org/10.2210/rcsb_pdb/mom_2005_9 10.2210/rcsb_pdb/mom_2005_9]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XTC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1XTC FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1xtc]] is a 7 chain structure with sequence from [https://en.wikipedia.org/wiki/Vibrio_cholerae_569B Vibrio cholerae 569B]. The September 2005 RCSB PDB [https://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Cholera Toxin'' by David S. Goodsell is [https://dx.doi.org/10.2210/rcsb_pdb/mom_2005_9 10.2210/rcsb_pdb/mom_2005_9]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XTC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1XTC FirstGlance]. <br> |
| - | </td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1xtc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xtc OCA], [https://pdbe.org/1xtc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1xtc RCSB], [https://www.ebi.ac.uk/pdbsum/1xtc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1xtc ProSAT]</span></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.4Å</td></tr> |
| | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1xtc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xtc OCA], [https://pdbe.org/1xtc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1xtc RCSB], [https://www.ebi.ac.uk/pdbsum/1xtc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1xtc ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[https://www.uniprot.org/uniprot/CHTA_VIBCH CHTA_VIBCH]] The A1 chain catalyzes the ADP-ribosylation of Gs alpha, a GTP-binding regulatory protein, to activate the adenylate cyclase. This leads to an overproduction of cAMP and eventually to a hypersecretion of chloride and bicarbonate followed by water, resulting in the characteristic cholera stool. The A2 chain tethers A1 to the pentameric ring. [[https://www.uniprot.org/uniprot/CHTB_VIBCH CHTB_VIBCH]] 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.
| + | [https://www.uniprot.org/uniprot/CHTA_VIBCH CHTA_VIBCH] The A1 chain catalyzes the ADP-ribosylation of Gs alpha, a GTP-binding regulatory protein, to activate the adenylate cyclase. This leads to an overproduction of cAMP and eventually to a hypersecretion of chloride and bicarbonate followed by water, resulting in the characteristic cholera stool. The A2 chain tethers A1 to the pentameric ring. |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
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| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| | [[Category: RCSB PDB Molecule of the Month]] | | [[Category: RCSB PDB Molecule of the Month]] |
| - | [[Category: Vibrio cholerae]] | + | [[Category: Vibrio cholerae 569B]] |
| - | [[Category: Westbrook, E]] | + | [[Category: Westbrook E]] |
| - | [[Category: Zhang, R G]] | + | [[Category: Zhang R-G]] |
| - | [[Category: Enterotoxin]]
| + | |
| - | [[Category: Toxin]]
| + | |
| Structural highlights
Function
CHTA_VIBCH The A1 chain catalyzes the ADP-ribosylation of Gs alpha, a GTP-binding regulatory protein, to activate the adenylate cyclase. This leads to an overproduction of cAMP and eventually to a hypersecretion of chloride and bicarbonate followed by water, resulting in the characteristic cholera stool. The A2 chain tethers A1 to the pentameric ring.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The clinical manifestations of cholera are largely attributable to the actions of a secreted hexameric AB5 enterotoxin (choleragen). We have independently solved and refined the three-dimensional structure of choleragen at 2.5 A resolution. The structure of the crystalline toxin closely resembles that described for the heat-labile enterotoxin from Escherichia coli (LT) with which it shares 80% sequence homology. In both cases, the wedge-shaped A subunit is loosely held high above the plane of the pentameric B subunits by the tethering A2 chain. The most striking difference between the two toxins occurs at the carboxyl terminus of the A2 chain. Whereas the last 14 residues of the A2 chain of LT threading through the central pore of the B5 assembly form an extended chain with a terminal loop, the A2 chain of choleragen remains a nearly continuous alpha-helix throughout its length. The four carboxyl-terminal residues of the A2 chain (KDEL sequence), disordered in the crystal structure of LT, are clearly visible in choleragen's electron-density map. In the accompanying article we describe the three-dimensional structure of the isolated B pentamer of cholera toxin (choleragenoid). Comparison of the crystalline coordinates of choleragen, choleragenoid, and LT provides a solid three-dimensional foundation for further experimental investigation. These structures, along with those of related toxins from Shigella dysenteria and Bordetella pertussis, offer a first step towards the rational design of new vaccines and anti-microbial agents.
The three-dimensional crystal structure of cholera toxin.,Zhang RG, Scott DL, Westbrook ML, Nance S, Spangler BD, Shipley GG, Westbrook EM J Mol Biol. 1995 Aug 25;251(4):563-73. PMID:7658473[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Zhang RG, Scott DL, Westbrook ML, Nance S, Spangler BD, Shipley GG, Westbrook EM. The three-dimensional crystal structure of cholera toxin. J Mol Biol. 1995 Aug 25;251(4):563-73. PMID:7658473 doi:http://dx.doi.org/10.1006/jmbi.1995.0456
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