Secondary structure of the 58-nt L11-binding domain of 23S rRNA.

The four stems of the four-way junction are coded in different colors: green, helix A; gold, helix B; maroon, the 1082-1086 stem-loop; and blue, helix C. Hydrogen-bonded base pairings are indicated as dots. Nucleotides 1060-1061 and 1077-1078 comprise an internal loop in helix A, whereas two nucleotides, A1088 and G1089, form a bulge in helix C. The 1082-1086 stem-loop is closed by a lone U•A base pair.