Database URL Description BioGRID [43] http://thebiogrid.org/  Manually curated protein and genetic interactions for major model organisms IntAct [44] http://www.ebi.ac.uk/intact/  Manually curated molecular interactions, including comprehensive data about their source experiments NDB [42] http://ndbserver.rutgers.edu/  Nucleic acid and DNA/RNA-protein complex structures, including derived data for nucleic acids NPInter [18] http://www.panrna.org/NPInter/index.php  Functional interactions of ncRNAs and protein-related biomolecules, classified into categories based on interaction type PDB [10] http://www.rcsb.org/pdb/home/home.do  Experimentally determined three-dimensional structures PRD [45] http://pri.hgc.jp/  RPIs from 22 species, focusing on gene-level information PRIDB [24] http://pridb.gdcb.iastate.edu/  Interface information from RNA-protein complex structures in browsable and machine-readable format RBPDB [8] http://rbpdb.ccbr.utoronto.ca/   Experimental data on binding preferences and specificities of RBPs RPIntDB http://pridb.gdcb.iastate.edu/RPISeq/  RPIs from databases and high-throughput experiments in literature

Table 2: Databases of RNA-Protein Interactions and Interfaces.