RNA aptamers as tools for the purification and analysis of in vivo assembled ribonucleoproteins

RNA aptamer interactions with chromatography resins. Noncovalent interactions are denoted as triple dotted lines and the respective dissociation constant (K_D), and elution of the RNP occurs through disrupting these interactions, for example, by adding competing molecules. (A) Some RNA aptamers (orange) can interact directly with the chromatography resin. (B) Small ligand-binding RNA aptamers bind to chemical groups, which are covalently linked to the resin. (C) Protein-binding RNA aptamers interact with a protein (light blue, K_D1) that itself interacts noncovalently with the resin (K_D2), typically through a functional group linked to the resin.