FIG. 3.

Natural anti-TF RNA aptamers. (A) Escherichia coli 6S RNA. Schematic of 6S RNA secondary structure, adapted from Wassarman [33]. (B) Schematic of caudal (cad) mRNA showing 940-nucleotide transcript. Highlighted in green is the region found to interact with bicoid protein, termed the bcd recognition element (BRE). The hairpin depicted in this region is a hypothetical secondary structure proposed for the interaction with bcd. (C) Hypothetical trophoblast STAT utron (TSU) model involving base pairing of promoter-like motifs 1 and 8 in TSU. (D) Synthetic TSU model RNA based on GAS motifs in loop–loop bent helical structures. C and D adapted from Peyman [47].