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| | <StructureSection load='1s5d' size='340' side='right'caption='[[1s5d]], [[Resolution|resolution]] 1.75Å' scene=''> | | <StructureSection load='1s5d' size='340' side='right'caption='[[1s5d]], [[Resolution|resolution]] 1.75Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1s5d]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/"bacillo_virgola_del_koch"_trevisan_1884 "bacillo virgola del koch" trevisan 1884]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1S5D OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1S5D FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1s5d]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Vibrio_cholerae Vibrio cholerae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1S5D OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1S5D FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GAL:BETA-D-GALACTOSE'>GAL</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></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]] 1.75Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1xtc|1xtc]], [[1lts|1lts]], [[1ltg|1ltg]], [[1lta|1lta]]</div></td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GAL:BETA-D-GALACTOSE'>GAL</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">CTXA, TOXA, VC1457 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=666 "Bacillo virgola del Koch" Trevisan 1884]), CTXB, TOXB, VC1456 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=666 "Bacillo virgola del Koch" Trevisan 1884])</td></tr> | + | |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/NAD(+)--diphthamide_ADP-ribosyltransferase NAD(+)--diphthamide ADP-ribosyltransferase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.2.36 2.4.2.36] </span></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=1s5d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1s5d OCA], [https://pdbe.org/1s5d PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1s5d RCSB], [https://www.ebi.ac.uk/pdbsum/1s5d PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1s5d ProSAT]</span></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=1s5d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1s5d OCA], [https://pdbe.org/1s5d PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1s5d RCSB], [https://www.ebi.ac.uk/pdbsum/1s5d PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1s5d 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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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Bacillo virgola del koch trevisan 1884]] | |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Amaya, E I]] | + | [[Category: Vibrio cholerae]] |
| - | [[Category: Hol, W G]] | + | [[Category: Amaya EI]] |
| - | [[Category: Holmes, R K]] | + | [[Category: Hol WG]] |
| - | [[Category: Jobling, M G]] | + | [[Category: Holmes RK]] |
| - | [[Category: Neal, C J.O]] | + | [[Category: Jobling MG]] |
| - | [[Category: Ab5 toxin]] | + | [[Category: O'Neal CJ]] |
| - | [[Category: Adp ribose transferase]]
| + | |
| - | [[Category: Cholera toxin]]
| + | |
| - | [[Category: Heat-labile enterotoxin]]
| + | |
| - | [[Category: Toxin]]
| + | |
| - | [[Category: Transferase]]
| + | |
| 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
Cholera toxin (CT) is a heterohexameric bacterial protein toxin belonging to a larger family of A/B ADP-ribosylating toxins. Each of these toxins undergoes limited proteolysis and/or disulfide bond reduction to form the enzymatically active toxic fragment. Nicking and reduction render both CT and the closely related heat-labile enterotoxin from Escherichia coli (LT) unstable in solution, thus far preventing a full structural understanding of the conformational changes resulting from toxin activation. We present the first structural glimpse of an active CT in structures from three crystal forms of a single-site A-subunit CT variant, Y30S, which requires no activational modifications for full activity. We also redetermined the structure of the wild-type, proenzyme CT from two crystal forms, both of which exhibit (i) better geometry and (ii) a different A2 "tail" conformation than the previously determined structure [Zhang et al. (1995) J. Mol. Biol. 251, 563-573]. Differences between wild-type CT and active CTY30S are observed in A-subunit loop regions that had been previously implicated in activation by analysis of the structure of an LT A-subunit R7K variant [van den Akker et al. (1995) Biochemistry 34, 10996-11004]. The 25-36 activation loop is disordered in CTY30S, while the 47-56 active site loop displays varying degrees of order in the three CTY30S structures, suggesting that disorder in the activation loop predisposes the active site loop to a greater degree of flexibility than that found in unactivated wild-type CT. On the basis of these six new views of the CT holotoxin, we propose a model for how the activational modifications experienced by wild-type CT are communicated to the active site.
Crystal structures of an intrinsically active cholera toxin mutant yield insight into the toxin activation mechanism.,O'Neal CJ, Amaya EI, Jobling MG, Holmes RK, Hol WG Biochemistry. 2004 Apr 6;43(13):3772-82. PMID:15049684[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ O'Neal CJ, Amaya EI, Jobling MG, Holmes RK, Hol WG. Crystal structures of an intrinsically active cholera toxin mutant yield insight into the toxin activation mechanism. Biochemistry. 2004 Apr 6;43(13):3772-82. PMID:15049684 doi:http://dx.doi.org/10.1021/bi0360152
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