Pyrimidine-specific cleavage by an endoribonuclease of Saccharomyces cerevisiae.
An endoribonuclease with pyrimidine cleavage site specificity was isolated from Saccharomyces cerevisiae. The enzyme had a pH optimum of 6 to 7 and did not require a divalent cation. It was inhibited by 5 X 10(-5) M ethidium bromide, although it appeared to be single strand specific. The enzyme gave a limited cleavage of yeast mRNA and rRNA, yielding products that were terminated with pyrimidine nucleoside 2',3'-cyclic phosphate. The bonds between pyrimidine and A residues constituted more than 90% of the scission sites when the average product size was 50 nucleotides. Homopolyribonucleotides were cleaved poorly. Poly(A,U) was cleaved rapidly, and analysis of the products of poly(A,U) hydrolysis showed a very stringent cleavage of U-A bonds.
D004722:Endoribonucleases / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D011063:Poly A-U / Q000378:metabolism; D011743:Pyrimidines / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013379:Substrate Specificity
D011743:Pyrimidines; D012333:RNA, Messenger; D011063:Poly A-U; D004722:Endoribonucleases