Sakaguchi K, Boyd J B
J Biol Chem. 1985 Sep 5;260(19):10406-11.
A DNA polymerase with properties similar to mammalian polymerase beta has been isolated to near homogeneity from embryos of Drosophila melanogaster. A combination of exclusion chromatography and sodium dodecyl sulfate-gel electrophoresis indicates that this enzyme is composed of a single polypeptide of molecular weight-110,000. Optimum activity on a nicked template occurs at pH 8.4 in the presence of 15 mM MgCl2 and 250 mM NaCl. Enzyme activity is strongly inhibited by dideoxythymidine triphosphate but is relatively insensitive to aphidicolin and N-ethylmalemide. These properties clearly distinguish this enzyme from polymerase alpha, which has previously been characterized from this tissue. This report represents the first extensive purification of a beta-like polymerase from the Protostomic branch of the animal phylogenetic tree. It furthermore generates the potential for a genetic analysis of the function of polymerase beta in DNA recombination, repair, and synthesis.
已从黑腹果蝇胚胎中分离出一种性质与哺乳动物β聚合酶相似的DNA聚合酶，纯度接近均一。排阻色谱法和十二烷基硫酸钠-凝胶电泳相结合表明，这种酶由一条分子量为110,000的单一多肽组成。在有缺口的模板上，最佳活性出现在pH 8.4、15 mM氯化镁和250 mM氯化钠存在的条件下。双脱氧胸苷三磷酸强烈抑制酶活性，但对阿非科林和N-乙基马来酰胺相对不敏感。这些特性清楚地将这种酶与先前已从该组织中鉴定出来的α聚合酶区分开来。本报告首次对动物系统发育树原口动物分支中的一种类β聚合酶进行了广泛纯化。此外，这为对β聚合酶在DNA重组、修复和合成中的功能进行遗传分析创造了可能性。
