title: Endoribonuclease IV. A poly(A)-specific ribonuclease from chick oviduct. 1. Purification of the enzyme.
abstract: A new endoribonuclease, termed endoribonuclease IV, has been described. This enzyme has been isolated from chick oviducts and purified 15 000-fold in a 25% yield nearly to homogeneity. The nuclease, which specifically degrades poly(A), forms oligonucleotides of an average chain length of 10. These (A)-10 fragments are terminated by 3'-hydroxyl and 5'-phosphate groups. The enzyme has a pH optimum at 8.7, requires Mn2+ or Mg2+ as a cofactor, and has a molecular weight of about 45 000.
mesh_terms: D000818:Animals; D002645:Chickens; D004720:Endonucleases / Q000302:isolation & purification / Q000378:metabolism; D004789:Enzyme Activation; D005260:Female; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D008970:Molecular Weight; D009843:Oligoribonucleotides / Q000032:analysis; D010057:Oviducts / Q000201:enzymology*; D011061:Poly A; D012260:Ribonucleases / Q000302:isolation & purification / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D009843:Oligoribonucleotides; D011061:Poly A; D008345:Manganese; D004720:Endonucleases; D012260:Ribonucleases; D008274:Magnesium