title: Purification of a base-specific ribonuclease Ru from Rhizopus niveus.
abstract: A base-specific ribonuclease (RNase) Ru (EC 3.1.27.5) was isolated and purified from Rhizopus niveus in a yield of 17% by the procedures of acetone precipitation, column chromatography on Duolite A-2, DEAE-cellulose, CM-cellulose, and 2'(3')-aminohexyl-5'-UMP-agarose. The enzyme was shown to be homogeneous by polyacrylamide disc electrophoresis. The amino- and carboxyl-terminal amino acids of the enzyme were determined to be an arginine and an aspartic acid, respectively. The enzyme has a base specificity: it released only 3'-UMP from yeast RNA or poly(U) and, in addition, small amounts of 3'-CMP from poly(C).
mesh_terms: D000596:Amino Acids / Q000032:analysis; D003568:Cytidine Monophosphate / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004720:Endonucleases / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D011066:Poly C / Q000378:metabolism; D011072:Poly U / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D012233:Rhizopus / Q000201:enzymology*; D012259:Ribonuclease, Pancreatic; D012260:Ribonucleases / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity; D014500:Uracil Nucleotides / Q000378:metabolism*; D014542:Uridine Monophosphate / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D014500:Uracil Nucleotides; D011072:Poly U; D011066:Poly C; D012313:RNA; D014542:Uridine Monophosphate; D004720:Endonucleases; D012260:Ribonucleases; D012259:Ribonuclease, Pancreatic; D003568:Cytidine Monophosphate