Figure 5.

Schematic fold of the apical stem–loop of ε. In the loop and bulges, important structural features are indicated, such as sugar puckering (green box, >40% S; blue box, <40% S; white box, N), non-helical phosphorus shifts (red circles) and NOE contacts (solid lines). Dotted lines indicate weaker contacts. Thick red lines indicate imino–imino contacts. The contact between H8 G22 and H8 G24 is very weak, making it uncertain whether it is a true contact or a noise peak. The H1′ G22 to H6 U23 could not be seen due to overlap between H1′ G22 and H5 U23. However, the H2′ G22 to H6 U23 NOE is clearly visible (data not shown). The ³¹P with resonances slightly shifted from the bulk (Materials and Methods) are indicated in red.