Figure 7. Interaction of PKR with dsRNAs containing 2'-O-methyl barriers.

(A) Schematic of 2'-O-methyl (2'-O-Me) barrier-containing dsRNAs. Chimeric dsRNAs were designed to contain 5, 10 and 15 bp 2'-O-Me barriers inserted between two 15 bp dsRNA regions. (B) Activation of WT PKR by 2'-O-Me barrier-containing dsRNAs. The percent activation is normalized to the signal from the 40 bp dsRNA at 100 nM. (C) Anisotropy titration of pAzF-261-A488 PKR with 2'-O-Me barrier-containing dsRNAs. For reference, the maximal anisotropy changes associated with PKR binding to regular 30 and 40 bp dsRNAs are indicated by arrows. (D) Fractional concentrations of the 1:2 RNA:PKR complex (RP₂) for PKR binding to the 2'-O-Me barrier-containing dsRNAs. The fractional concentrations were determined using the experimentally determined dissociation constants (Table 1). The maximal fraction of RP₂ for PKR binding to a 40 bp dsRNA is indicated with an arrow.