Embracing proteins: structural themes in aptamer-protein complexes

- Traditional aptamers fold into structures with established nucleic acid motifs.
- Modified nucleotides expand the repertoire of known nucleic acid structural motifs.
- Hydrophobic modifications make essential inter-molecular and intramolecular interactions.
- The flexible phosphodiester bond of aptamers allows for high shape complementarity.
- In most cases, aptamer binding occurs without a conformational change of the target.