EC Explorer

4.6.1.18

pancreatic ribonuclease

(1) an [RNA] containing cytidine + H₂O = an [RNA]-3′-cytidine-3′-phosphate + a 5′-hydroxy-ribonucleotide-3′-[RNA] (overall reaction);;(1a) an [RNA] containing cytidine = an [RNA]-3′-cytidine-2′,3′-cyclophosphate + a 5′-hydroxy-ribonucleotide-3′-[RNA];;(1b) an [RNA]-3′-cytidine-2′,3′-cyclophosphate + H₂O = an [RNA]-3′-cytidine-3′-phosphate;;(2) an [RNA] containing uridine + H₂O = an [RNA]-3′-uridine-3′-phosphate + a 5′-hydroxy-ribonucleotide-3′-[RNA];;(2a) an [RNA] containing uridine = an [RNA]-3′-uridine-2′,3′-cyclophosphate + a 5′-hydroxy-ribonucleotide-3′-[RNA];;(2b) an [RNA]-3′-uridine-2′,3′-cyclophosphate + H₂O = an [RNA]-3′-uridine-3′-phosphate

RNase, RNase I, RNase A, pancreatic RNase, ribonuclease I, endoribonuclease I, ribonucleic phosphatase, alkaline ribonuclease, ribonuclease, gene S glycoproteins, Ceratitis capitata alkaline ribonuclease, SLSG glycoproteins, gene S locus-specific glycoproteins, S-genotype-asssocd. glycoproteins, ribonucleate 3′-pyrimidino-oligonucleotidohydrolase

RNA lyase ([RNA]-3′-cytidine/uridine-3′-phosphate and 5′-hydroxy-ribonucleotide-3′-[RNA] producing)

9001-99-4

Specifically cleaves at the 3′-side of pyrimidine (uracil or cytosine) phosphate bonds in RNA. The reaction takes place in two steps, with the 2′,3′-cyclic phosphodiester intermediates released from the enzyme at the completion of the first step. Hydrolysis of these cyclic compounds occurs at a much slower rate through a reversal of the first step, in which the -OH group of water substitutes for the 2′-OH group of the ribose used in the first step, and does not take place until essentially all the susceptible 3′,5′-phosphodiester bonds have been cyclised. The enzyme can act as an endo- or exo ribonuclease.

created 1972 as EC 3.1.4.22, transferred 1978 to EC 3.1.27.5, modified 1981, transferred 2018 to EC 4.6.1.18