Table 1. Comparison of content for similarly intended databases and web accessible resources involving base motifs in RNA structures.

	NCIR	RNAJunction	RNA 3D Motif Atlas	RNA Bricks	InterRNA
Base pair	Yes	No	Yes	No	Yes
Base interaction clusters ranging from triples to sextuples	Yes. Contains base-triples, quadruples and quintuples	No	Yes. Only contains base-triples via RNA Triple Database	No	Yes. Contains base-triples, quadruples, quintuples and sextuples
Ribose-zippers	No	No	No	No	Yes
A/G-minor motifs	No	No	No	No	Yes
Hairpin Loop	No	No	Yes. Contains tetraloop (GNRA) & T-loop	Yes. Displays all the loops based on PDB ID. No classification is provided for the loops	Yes. Contains tetraloops (GNRA, UNCG & CUUG) and T-loops
Internal Loop	No	No	Yes. Contains C-loop, kink-turn, sarcin-ricin, triple sheared and double sheared	Yes. Displays all the loops based on PDB ID. No classification is provided for the loops	Yes. Only contains kink-turn (in the manually curated data set)
Junction Loop	No	Yes	No	Yes. Displays all the loops based on PDB ID. No classification is provided for the loops	No
Kissing Loop	No	Yes	No	No	No
Stems	No	No	No	Yes. Displays the stems based on PDB ID	No