Dissociation of two polypeptide chains from yeast RNA polymerase A.
Dissociation of two polypeptide chains from yeast RNA polymerase A.
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两条多肽链从酵母 RNA 聚合酶 A 上解离。
DOI：
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发表时间：
1975
影响因子：
11.1
通讯作者：
P. Fromageot
中科院分区：
文献类型：
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作者：
J. Huet;J. Buhler;A. Sentenac;P. Fromageot
酵母RNA聚合酶A（RNA核苷酸转移酶;核苷三磷酸：RNA核苷酸转移酶; EC 2.7.7.6）可以转化为一种新形式的酶，称为RNA聚合酶A*，它缺少两条48，000和37，000道尔顿的多肽链。除了这两个缺失的多肽，RNA聚合酶A和A* 的亚基结构是不可区分的。RNA聚合酶A* 在其电泳和色谱行为、模板要求和α-鹅膏蕈碱敏感性方面与完整酶不同。RNA聚合酶A* 以与RNA聚合酶A相同的效率转录交替共聚物d（A-T）n，但其比活性以天然小牛胸腺DNA为模板大大降低。多种合成模板的转录也通过去除两条多肽链而改变。RNA聚合酶A* 被高浓度的α-鹅膏蕈碱（500 μ g/ml）抑制，而RNA聚合酶A对毒性肽的敏感性相对较低。的数据进行了讨论的两个可分离的多肽的可能的作用。
Yeast RNA polymerase A (RNA nucleotidyltransferase; nucleosidetriphosphate:RNA nucleotidyltransferase; EC 2.7.7.6) can be converted to a new form of enzyme, called RNA polymerase A*, which is lacking two polypeptide chains of 48,000 and 37,000 daltons. Apart from these two missing polypeptides the subunit structures of RNA polymerases A and A* are indistinguishable. RNA polymerase A* differs from the complete enzyme in its electrophoretic and chromatographic behavior, template requirements, and alpha-amanitin sensitivity. RNA polymerase A* transcribes the alternated copolymer d(A-T)n with the same efficiency as RNA polymerase A but its specific activity is greatly reduced with native calf thymus DNA as template. The transcription of a variety of synthetic templates is also altered by removal of the two polypeptide chains. RNA polymerase A* is inhibited by high concentrations of alpha-amanitin (500 mug/ml), whereas RNA polymerase A is comparatively less sensitive to the toxic peptide. The data are discussed in terms of possible roles of the two dissociable polypeptides.