Binding of MIP and NS5A peptides to SH3 domain of other members of MLK subfamily (MLK1–4). To determine whether MIP and NS5A can interact with SH3 domains of MLK1–4 proteins, the purified GST-MLK1–4 SH3 domains were incubated with biotinylated peptides, NS5A peptide (KKAPTPPPRRRR-GGG-K-biotin), MIP (AIRINPNGTWSRQAETVES-K-biotin), and MIP-R12A (AIRINPNGTWSAQAETVES-K-biotin), immobilized on a NeutrAvidin-coated 96-well ELISA plate. Binding of SH3 domain was detected with anti-GST antibody conjugated to HRP. Experiments were performed in triplicate, and the results are an averaged value; error bars reflect the standard deviation of each point. See also Fig. S6.