<HTTP://PATHWAYCOMMONS.ORG/PSI2BP#RXR-3R21> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.biopax.org/release/biopax-level3.owl#RelationshipXref> .
<HTTP://PATHWAYCOMMONS.ORG/PSI2BP#RXR-3R21> <http://www.biopax.org/release/biopax-level3.owl#db> "rcsb pdb"^^<http://www.w3.org/2001/XMLSchema#string> .
<HTTP://PATHWAYCOMMONS.ORG/PSI2BP#RXR-3R21> <http://www.biopax.org/release/biopax-level3.owl#id> "3R21"^^<http://www.w3.org/2001/XMLSchema#string> .