The universally conserved nucleotides of the small subunit ribosomal RNAs

A base triple connecting helix h34 to helix h18. (A) Helix h34 contains three single-base and two 3-base bulge loops. (B) A532, which projects from the h18 pseudoknot (Fig. 9), makes a type XI A–G pair with G1206 in the minor groove of helix h34 (Fig. 12B). This interaction creates the sole noncovalent connection between h18 in the body domain and h34 of the head domain of the 30S subunit, two principal elements of the 30S A site.