Distinct contributions of KH domains to substrate binding affinity of Drosophila P-element somatic inhibitor protein

Binding affinity (K_d) experiments on KH03 and RNA. (A) RNA sequences used. (Full length) Δ11 sequence, (italics) PSI29, (underlined italics) PSI21. The positions of the F1 and F2 pseudo-splice sites are shown. (B) Representative native gel of wild-type KH03 binding to PSI21 RNA substrate. The K_d calculated from this experiment was 229 nM. (C) Plot of binding isotherms comparing wild-type KH03 on three separate substrates. (□) Δ11, (▴) PSI29, (○) PSI21, (♦) PL2.