Figure 3
Effect of amino acid substitutions on the RNA-binding activity of His 6 -TGBp2. A, B. Effects of substitutions of basic amino acid residues and tyrosine residues, respectively, on the RNA-binding activity of TGBp2. Equal amount of wild-type or mutant TGBp2 was assayed for the RNA-binding activity using UV-crosslinking assay. The TGBp2 proteins were run on SDS-polyacrylamide gel. Autoradiography (upper panel) and Coomassie blue staining (bottom panel) of TGBp2 protein in the binding samples were performed. W, wild-type TGBp2. The mutant TGBp2 proteins were designated as follows: N (R-9 and R-15 mutated to A), L (R-45, R-53 and K-59 mutated to A), C (R-92, R-103 and R-114 mutated to A), NC (R-9, R-15, R-92, R-103 and R-114 mutated to A), 54 (Y-54 mutated to A), 63 (Y-63 mutated to A), 70 (Y-70 mutated to A), 105 (Y-105 mutated to A).