Stevens A
J Bacteriol. 1985 Oct;164(1):57-62. doi: 10.1128/jb.164.1.57-62.1985.
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.
从酿酒酵母中分离出一种具有嘧啶切割位点特异性的核糖核酸内切酶。该酶的最适pH为6至7，不需要二价阳离子。它受到5×10⁻⁵M溴化乙锭的抑制，尽管它似乎具有单链特异性。该酶对酵母mRNA和rRNA进行有限切割，产生以嘧啶核苷2',3'-环磷酸酯结尾的产物。当平均产物大小为50个核苷酸时，嘧啶与A残基之间的键构成了超过90%的切割位点。同聚核糖核苷酸的切割效果较差。聚（A，U）被迅速切割，对聚（A，U）水解产物的分析表明U-A键的切割非常严格。
