3EJ5: Complex Of Ricin A Chain And Pyrimidine-based Inhibitor

Ricin is a potent heterodimeric cytotoxin; the B chain binds eucaryotic cell surfaces aiding uptake and the A chain, RTA, reaches the cytoplasm where it enzymatically depurinates a key ribosomal adenine, inhibiting protein synthesis. Ricin is known to be an agent in bioterrorist repertoires and there is great interest in finding, or creating, efficacious inhibitors of the toxin as potential antidotes. We have previously identified two families of bicyclic RTA inhibitors, pterins and purines. Both classes have poor solubility which impairs inhibitor development. Here we report the use of 2-amino-4,6-dihydroxy-pyrimidines as RTA inhibitors. Unlike previously observed single ring inhibitor platforms, these displace Tyr 80 and bind deep in the RTA specificity pocket. These compounds are at least 10 times more soluble than pterin-based inhibitors and appear to be useful new class of ricin inhibitors.
PDB ID: 3EJ5Download
MMDB ID: 70682
PDB Deposition Date: 2008/9/17
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 2.5  Å
Source Organism:
Similar Structures:
Biological Unit for 3EJ5: monomeric; determined by author and by software (PISA)
Molecular Components in 3EJ5
Label Count Molecule
Protein (1 molecule)
Ricin a Chain(Gene symbol: LOC8261245)
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB