View source for 4hup


==Structure of ricin A chain bound with N-(N-(pterin-7-yl)carbonylglycyl)-L-phenylalanyl)-L-phenylalanine==
<StructureSection load='4hup' size='340' side='right'caption='[[4hup]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4hup]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Ricinus_communis Ricinus communis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4HUP OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4HUP 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]] 1.699&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=19M:(2S)-2-[[(2S)-2-[2-[(2-AZANYL-4-OXIDANYLIDENE-1H-PTERIDIN-7-YL)CARBONYLAMINO]ETHANOYLAMINO]-3-PHENYL-PROPANOYL]AMINO]-3-PHENYL-PROPANOIC+ACID'>19M</scene>, <scene name='pdbligand=MLA:MALONIC+ACID'>MLA</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=4hup FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hup OCA], [https://pdbe.org/4hup PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4hup RCSB], [https://www.ebi.ac.uk/pdbsum/4hup PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4hup ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RICI_RICCO RICI_RICCO] Ricin is highly toxic to animal cells and to a lesser extent to plant cells. The A chain acts as a glycosidase that removes a specific adenine residue from an exposed loop of the 28S rRNA (A4324 in mammals), leading to rRNA breakage. As this loop is involved in elongation factor binding, modified ribosomes are catalytically inactive and unable to support protein synthesis. The A chain can inactivate a few thousand ribosomes per minute, faster than the cell can make new ones. Therefore a single A chain molecule can kill an animal cell. The B chain binds to beta-D-galactopyranoside moieties on cell surface glycoproteins and glycolipids and facilitates the entry into the cell of the A chain; B chains are also responsible for cell agglutination (Lectin activity).
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== Publication Abstract from PubMed ==
Several 7-peptide-substituted pterins were synthesized and tested as competitive active-site inhibitors of ricin toxin A (RTA). Focus began on dipeptide conjugates, and these results further guided the construction of several tripeptide conjugates. The binding of these compounds to RTA was studied via a luminescence-based kinetic assay, as well as through X-ray crystallography. Despite the relatively polar, solvent exposed active site, several hydrophobic interactions, most commonly pi-interactions not predicted by modeling programs, were identified in all of the best-performing inhibitors. Nearly all of these compounds provide IC(50) values in the low micromolar range.

Peptide-Conjugated Pterins as Inhibitors of Ricin Toxin A.,Saito R, Pruet JM, Manzano LA, Jasheway K, Monzingo AF, Wiget PA, Kamat I, Anslyn EV, Robertus JD J Med Chem. 2012 Dec 19. PMID:23214944<ref>PMID:23214944</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4hup" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ricin 3D structures|Ricin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Ricinus communis]]
[[Category: Anslyn EV]]
[[Category: Jasheway KR]]
[[Category: Manzano LA]]
[[Category: Monzingo AF]]
[[Category: Pruet JM]]
[[Category: Robertus JD]]
[[Category: Saito R]]
[[Category: Wiget PA]]