Table 1.

RNA selected with the anti-NES antibodies (XAPs)

The XAP sequences corresponding to the initially variable part of the library are aligned. The common features are four groups of three G residues (in boldface type; note that one G residue of each group originated from the variable loops) and a maximum length of 3 nucleotides in loops 1–4. RNAs lacking a third G residue in one of the groups, or containing 4 nucleotides in one of the loops 2–4 are not binding detectably. Shown also are the sequences of variants (V_GGG, V_GUG, V_GG) designed to investigate the importance of a G scaffold. There, the constant features were the loop sequences (in boldface type). In V_TL the stem is closed by a stable tetraloop sequence; the constant sequence of the stems is not shown.