Nucleic acids - DNA and RNA - play the key informational role in the cell. But they are also structural, regulatory, and they can even behave like enzymes.
The DNA in the nucleus bearing the genetic blueprint is frequently copied and transcribed by DNA and RNA polymerases. Yet DNA is wrapped up in chromatin structure and must be manipulated by topoisomerases and helicases to allow its access and usage.
RNA achieves complex folds that can recognize and bind small molecules, itself be recognized by proteins, and accelerate chemical reactions by a million fold or more.
We are beginning to learn how nucleic acids can achieve these feats.