Non-GNRA-like loop structures that interact with helices.

1“Indiv” indicates an individual structure that does not form an additional level of subgrouping based on superposition. “NTL” denotes a loop that does not consist of four nucleotides (non-tetraloop).2“++” indicates at most minor deviations between the electron density map and the specific modeled substructure (∼8–15 nts). “+” indicates a greater degree of unmodeled positive or negative electron density.3Haloarcula structural portions found in the E. coli ribosome with essentially identical structures. The E. coli structures are omitted from the table.4The electron density indicates that base 1835 should be flipped 180 degrees around the glycosidic bond.