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.1. “Indiv” 指不基于叠加形成额外亚组层级的个体结构；“NTL” 指代不含四个核苷酸的环（non-tetraloop，非四核苷酸环）。 2. “++” 表示电子密度图与特定建模亚结构（约8~15个核苷酸）之间至多存在微小偏差；“+” 则代表存在程度更显著的未建模正负电子密度。 3. 大肠杆菌核糖体中存在的盐杆菌属（Haloarcula）结构区段，其结构与盐杆菌原生结构基本一致，因此大肠杆菌的相关结构未列入本表。 4. 电子密度分析结果表明，碱基1835需围绕糖苷键发生180°翻转。