Figure 5.

The effect of mutations in the GluR-B Q/R and R/G site RNA on editing activity. (A) Editing activity of Q/R site mutations. (B) Editing activity of R/G site mutations. The potential secondary structure of the 58 nucleotide R/G site substrate and a similar 323 nucleotide Q/R site substrate are shown on the top of A and B. Two base mismatches at A₁₃ and G₂₀ of Q/R site, or A₁₁ and G₁₅ of the R/G site RNA were mutated to evaluate their importance for editing efficiency by rRED1. Editing efficiency was determined as in Fig. 3B. Mutations are denoted by the mismatched nucleotide and its position followed by its potential base paired nucleotide and its position. A₁₃C₃₀₉ and A₁₁C₄₇ are the wild-type substrates for Q/R and R/Q sites. In G₁₃C_309, nucleotide 13 of the Q/R site RNA is replaced by G. In A₁₃U_309, nucleotide 309 of Q/R site RNA is replaced by U. A₁₃U₃₀₉/G₂₀C₃₀₂ is a double mutation in which nucleotides 309 and 302 of the Q/R site RNA are replaced by U and C, respectively. The same nomenclature applies to the R/G site RNA mutations.