Figure 1.

Development of MST‐based competition binding assay to assess the influence of oligoadenylate modification on PABP interactions. A) Assay overview. B) Structure of PABP¹⁻¹⁹⁰ (RRM1/2; blue) in complex with poly(A) chain (yellow); PDB entry 4F02 by Safaee et al. ^[14] eIF4G protein PABP‐binding site is marked in green. C) Binding of 5’‐FAM−A12 by PABP. Top: MST traces from a typical direct binding experiment. Blue and red indicate cold and hot regions used for further analysis (temp. jump mode). Bottom: binding curve fitted to the MST data using a 1 : 1 binding model. D) Competition experiment; A₁₂ ligand replaces 5’‐FAM‐A₁₂ probe in the binding pocket of PABP¹⁻¹⁹⁰ binding pocket, resulting in a reversed curve.