Ribonuclease U2 (EC3.1.27.4, purine specific endoribonuclease, ribonuclease U3, RNase U3, RNase U2, purine-specific ribonuclease, purine-specific RNase, Pleospora RNase, Trichoderma koningi RNase III, ribonuclease (purine)) is an enzyme.[1][2][3] This enzyme catalyses the following chemical reaction
Two-stage endonucleolytic cleavage to nucleoside 3'-phosphates and 3'-phosphooligonucleotides ending in Ap or Gp with 2',3'-cyclic phosphate intermediates
^Glitz DG, Dekker CA (October 1964). "Studies on a ribonuclease from Ustilago sphaerogena. I. Purification and properties of the enzyme". Biochemistry. 3 (10): 1391–9. doi:10.1021/bi00898a001. PMID14230791.
^Glitz DG, Dekker CA (October 1964). "Studies on a ribonuclease from Ustilago sphaerogena. II. Specificity of the enzyme". Biochemistry. 3 (10): 1399–406. doi:10.1021/bi00898a002. PMID14230792.
^Uchida T, Egami F (1971). "Microbial ribonucleases with special reference to RNases T1, T 2, N 1, and U2". In Boyer PD (ed.). The Enzymes. Vol. 4 (3rd ed.). New York: Academic Press. pp. 205–250.