View source for 6oca


==Ricin A chain bound to VHH antibody V2G10==
<StructureSection load='6oca' size='340' side='right'caption='[[6oca]], [[Resolution|resolution]] 2.11&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6oca]] is a 4 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6OCA OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6OCA FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=PG4:TETRAETHYLENE+GLYCOL'>PG4</scene></td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/rRNA_N-glycosylase rRNA N-glycosylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.22 3.2.2.22] </span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6oca FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6oca OCA], [http://pdbe.org/6oca PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6oca RCSB], [http://www.ebi.ac.uk/pdbsum/6oca PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6oca ProSAT]</span></td></tr>
</table>
== Function ==
[[http://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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</StructureSection>
[[Category: Large Structures]]
[[Category: RRNA N-glycosylase]]
[[Category: Rudolph, M J]]
[[Category: Toxin]]