Pancreatic ribonuclease

Pancreatic ribonucleasea are pyrimidine-specific endonucleases found in high quantity in the pancreas of certain mammals and of some reptiles.

Specifically, the enzymes are involved in endonucleolytic cleavage of 3'-phosphomononucleotides and 3'-phosphooligonucleotides ending in C-P or U-P with 2',3'-cyclic phosphate intermediates. Ribonuclease can unwind the DNA helix by complexing with single-stranded DNA; the complex arises by an extended multi-site cation-anion interaction between lysine and arginine residues of the enzyme and phosphate groups of the nucleotides.

Other proteins belonging to the pancreatic RNAse family include: bovine seminal vesicle and brain ribonucleases; kidney non-secretory ribonucleases; liver-type ribonucleases; angiogenin, which induces vascularisation of normal and malignant tissues; eosinophil cationic protein, a cytotoxin and helminthotoxin with ribonuclease activity; and frog liver ribonuclease and frog sialic acid-binding lectin. The sequence of pancreatic RNases contains four conserved disulfide bonds and three amino acid residues involved in the catalytic activity.

Examples
Human genes encoding proteins containing this domain include:
 * ANG,
 * RNASE1, RNASE10, RNASE12, RNASE2, RNASE3, RNASE4, RNASE6, RNASE7, and RNASE8.