CATH Classification

Domain Context

CATH Clusters

Superfamily Ribonuclease A-like domain
Functional Family Ribonuclease pancreatic

Enzyme Information

4.6.1.18
Pancreatic ribonuclease.
based on mapping to UniProt P07998
(1) An (RNA) containing cytidine + H(2)O = an (RNA)-3'-cytidine- 3'-phosphate + a 5'-hydroxy-ribonucleotide-3'-(RNA). (2) An (RNA) containing uridine + H(2)O = an (RNA)-3'-uridine- 3'-phosphate + a 5'-hydroxy-ribonucleotide-3'-(RNA).
-!- 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. -!- Formerly EC 2.7.7.16, EC 3.1.4.22 and EC 3.1.27.5.

UniProtKB Entries (1)

P13489
RINI_HUMAN
Homo sapiens
Ribonuclease inhibitor

PDB Structure

PDB 2Q4G
External Links
Method X-RAY DIFFRACTION
Organism Escherichia
Primary Citation
Inhibition of human pancreatic ribonuclease by the human ribonuclease inhibitor protein.
Johnson, R.J., McCoy, J.G., Bingman, C.A., Phillips Jr., G.N., Raines, R.T.
J.Mol.Biol.