Alkaline ribonuclease from rye germ cytosol.
1. Alkaline ribonuclease (pH optimum 7.6) was isolated from rye (Secale cereale L) germ cytosol and partially purified; the preparation was devoid of other nucleolytic activities. 2. The enzyme is a typical endonuclease hydrolysing all phosphodiester bonds in RNA, yielding ultimately purine and pyrimidine nucleoside 2',3'-cyclic phosphates and the corresponding 3'-phosphates. Upon extensive digestion of synthetic polyribonucleotides, pyrimidine, but not purine, nucleoside 3'-phosphates are formed. The enzyme does not hydrolyse synthetic purine cyclic nucleotides. 3. The enzyme does not depolymerize double-stranded complexes of poly(A) and poly(U). 4. Susceptibility to photooxidation and inhibition by 2-hydroxy-5-nitrobenzyl bromide and N-bromosuccinimide implies the involvement of tryptophan residue in the active centre of the enzyme.
D001665:Binding Sites; D003600:Cytosol / Q000201:enzymology*; D004720:Endonucleases / Q000302:isolation & purification / Q000378:metabolism* / Q000528:radiation effects; D006863:Hydrogen-Ion Concentration; D008027:Light; D010944:Plants / Q000201:enzymology*; D011061:Poly A / Q000378:metabolism; D011072:Poly U / Q000378:metabolism; D011131:Polyribonucleotides / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D012260:Ribonucleases / Q000302:isolation & purification / Q000378:metabolism* / Q000528:radiation effects; D012434:Secale / Q000201:enzymology; D013329:Structure-Activity Relationship
D011131:Polyribonucleotides; D011061:Poly A; D011072:Poly U; D012313:RNA; D004720:Endonucleases; D012260:Ribonucleases