20 28 29 5 13 12 3 110 FIGURE 4-40 S RNAS. Based on the known primary sequences of several hundred small rRNAs, the folded stem-loop structures shown here woul lave maximal base- pairing in(a) prokaryotic and(b) eukaryotic The existence of these stem-loops in rRNA in solution stem-loop structure The stems, which are base- paired double helices, numbered 1-40 have been found in both prokary otic and general, the length and position of the 40 helices are wel ceded by p or Estem-loop structure