Stereodiagrams of some hook-turns found in rRNAs. The secondary structure of each turn is shown to the left of the stereodiagram of the structure to which it corresponds. The sequences that correspond to the blue and purple strands in each secondary structure diagram are colored blue and purple in the stereodiagram. Light red and cyan sequences are the continuations of the purple and blue sequences, respectively. Green sequences represent other sequences that contact with the turn in question. (A) T. thermophilus 16S rRNA; (C527–C532 and A480–C484) pdb: 1i94. (B) D. radiodurans 23S rRNA; (C645–U650 and G636–C640) pdb: 1kc9. (C) H. marismortui 23S rRNA; (G2255–A2260 and C2241–U2246) pdb: 1jj2. (D) D. radiodurans 23S rRNA; (C610–C615 and U666–U670) pdb: 1kc9.
