2aai
From Proteopedia
Contents |
Crystallographic refinement of ricin to 2.5 Angstroms
Template:ABSTRACT PUBMED 1881880
Function
[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).
About this Structure
2aai is a 2 chain structure with sequence from Ricinus communis. The September 2005 RCSB PDB Molecule of the Month feature on Cholera Toxin by David S. Goodsell is 10.2210/rcsb_pdb/mom_2005_9. Full crystallographic information is available from OCA.
See Also
Reference
- Rutenber E, Katzin BJ, Ernst S, Collins EJ, Mlsna D, Ready MP, Robertus JD. Crystallographic refinement of ricin to 2.5 A. Proteins. 1991;10(3):240-50. PMID:1881880 doi:http://dx.doi.org/10.1002/prot.340100308
