Stepwise functionalization of ribonucleopeptide complexes to receptors and sensors.

We describe here stepwise functionalization strategies of ribonucleopeptide complexes to receptors and sensors. A structurally well-defined complex of RNA and peptide (ribonucleopeptide: RNP) was constructed by a structure-based design. The first step optimizes an ATP-binding characteristic of an RNP receptor based on an in vitro selection of an RNP library generated by introducing randomized nucleotide sequences in the RNA subunit. In the second step, the RNP receptor from the first step was functionalized to an RNP receptor for nicotinamide adenine dinucleotide (NAD+) or to ATP sensors by using respective modifications of the peptide subunit.