RNase S is a unique protein comprising the non-covalent association of two components, the S-peptide and the S-protein. An RNA-recognition segment derived from the human immunodeficiency virus (HIV)-1 Rev protein was conjugated with the S-peptide to form a complex with the S-protein. The resulting RNase S bearing the RNA-recognition segment preferentially hydrolyzed a single position of the RNA stem-loop derived from the specific binding site for the Rev protein.