A recombinant polypeptide is described including at least one PUF RNA-binding domain capable of specifically binding to a cytosine RNA base. The PUF RNA-binding domain of the polypeptide includes at least one RNA base-binding motif of the general formula X1X2X3X4X5X6X7X8X9X10X11 wherein X1 is selected from a defined group and wherein the RNA base-binding motif is operably capable of specifically binding to a cytosine RNA base.
