1s5c: Difference between revisions
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< | ==Cholera holotoxin with an A-subunit Y30S mutation, Crystal form 1== | ||
The | <StructureSection load='1s5c' size='340' side='right'caption='[[1s5c]], [[Resolution|resolution]] 2.50Å' scene=''> | ||
You may | == Structural highlights == | ||
or the | <table><tr><td colspan='2'>[[1s5c]] 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=1S5C OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1S5C FirstGlance]. <br> | ||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.5Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NA:SODIUM+ION'>NA</scene></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=1s5c FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1s5c OCA], [https://pdbe.org/1s5c PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1s5c RCSB], [https://www.ebi.ac.uk/pdbsum/1s5c PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1s5c ProSAT]</span></td></tr> | |||
</table> | |||
== 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. | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/s5/1s5c_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1s5c ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== 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<ref>PMID:15049684</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1s5c" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Cholera toxin 3D structures|Cholera toxin 3D structures]] | |||
*[[User:David Solfiell/sandbox 1|User:David Solfiell/sandbox 1]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
== | </StructureSection> | ||
[[Category: Large Structures]] | |||
== | |||
< | |||
[[Category: Vibrio cholerae]] | [[Category: Vibrio cholerae]] | ||
[[Category: Amaya | [[Category: Amaya EI]] | ||
[[Category: Hol | [[Category: Hol WG]] | ||
[[Category: Holmes | [[Category: Holmes RK]] | ||
[[Category: Jobling | [[Category: Jobling MG]] | ||
[[Category: Neal | [[Category: O'Neal CJ]] | ||