Figure 5.

Hydroxyl radical cleavage of aptamers bound to RT. The patterns of cleavage from representative hydroxyl radical digestions are shown. (A) R1T is subject to hyper-sensitive cleavage at position T9 when in complex with wt HXB2 RT but not when it is in complex with the E478Q mutant. Hypersensitive cleavage at position 9 is enhanced in the absence of EDTA (inset), which competes with RT for free Fe(II). (B) R1T variant Newtop shows a lack of a hypersensitive cleavage in its quadruplex. The secondary structure of Newtop is shown as inset.