Tutas D J, Paoletti E
J Biol Chem. 1977 May 10;252(9):3092-8.
A core-associated enzyme, designated as polynucleotide 5'-triphosphatase, has been purified from vaccinia. Fractionation on ADP-agarose of the soluble extract from detergent-disrupted cores followed by chromatography on poly(U)-agarose produced an 80-fold purification of the enzyme. The enzyme has an approximate molecular weight of 113,000 and is composed of two polypeptides with approximate molecular weights of 90,000 and 26,000. Divalent metal ions are necessary for enzymatic activity, which occurs optimally at pH 8.4. The enzyme acts upon 5'-ATP- and 5'-GTP-terminated RNA and also on 5'-ATP-terminated poly(A), catalyzing the hydrolysis of only the gamma-phosphate. The presumed biological role of the enzyme based upon this specificity is the participation in the initial step in the sequence of reactions through which the primary 5' termini of vaccinia messenger RNA are capped with the groups m7G(5')ppp(5')NmpN-.
一种与核心相关的酶，命名为多核苷酸5'-三磷酸酶，已从牛痘病毒中纯化出来。用去污剂破坏核心后的可溶性提取物在ADP-琼脂糖上进行分级分离，随后在聚（U）-琼脂糖上进行色谱分离，该酶得到了80倍的纯化。该酶的分子量约为113,000，由两条分子量约为90,000和26,000的多肽组成。二价金属离子是酶活性所必需的，其最佳活性发生在pH 8.4。该酶作用于5'-ATP和5'-GTP末端的RNA，也作用于5'-ATP末端的聚（A），仅催化γ-磷酸的水解。基于这种特异性推测该酶的生物学作用是参与牛痘信使RNA的初级5'末端被m7G(5')ppp(5')NmpN-基团加帽的反应序列的起始步骤。
