Ribonucleopeptides recognize the phosphotyrosine residue

Tools for selective recognition and sensing of kinase-catalyzed phosphorylation of Tyr or Ser/Thr residues located on a protein surface are essential for understanding signal transduction cascades of living cell. A stable complex of RNA and peptide (ribonucleopeptide) provides a new approach to tailor a receptor for small molecules. In vitro selection of an RNA-derived pool of ribonucleopeptide afforded a ribonucleopeptide receptor specific for phosphotyrosine (pTyr). Moreover, the ribonucleopeptide receptors are conveniently converted to fluorescent sensors for pTyr.