Subunits of RNA polymerase in function and structure. 7. Structure of premature core enzyme.
Subunits of RNA polymerase in function and structure. 7. Structure of premature core enzyme.
复制标题
RNA聚合酶亚基的功能和结构。
DOI：
10.1021/bi00573a006
复制
发表时间：
1979
期刊：
影响因子：
2.9
通讯作者：
S. Takahashi
中科院分区：
文献类型：
--
作者：
A. Ishihama;H. Aiba;T. Saitoh;S. Takahashi
对大肠杆菌DNA依赖性RNA聚合酶的体内、体外组装过程中的一个必需中间体--早熟核心酶的结构与天然核心酶的结构进行了比较。虽然这种组装，但无活性的形式的核心酶窝藏的总构象类似的天然酶，微小的和可能存在的局部差异，这是由近紫外圆二色光谱，氚-氢交换率，蛋白酶的敏感性，亚基间交联率由双功能试剂，沉降行为，和洗脱曲线从磷酸纤维素。总之，这些结果表明，核心酶亚基是松散地关联在早熟核心。温度依赖性成熟是核心亚基紧密结合所必需的，从而形成结构稳定且功能活性的RNA聚合酶。
The structure of premature core enzyme, an obligatory intermediate in both in vivo and in vitro assembly of Escherichia coli DNA-dependent RNA polymerase, was compared with that of native core enzyme. Though this assembled but inactive form of core enzyme harbors the gross conformation similar to that of native enzyme, minor and presumably local differences exist, which were identified by near-ultraviolet circular dichroism spectra, tritium-hydrogen exchange rate, protease sensitivity, intersubunit cross-linking rate by bifunctional reagents, sedimentation behavior, and elution profile from phosphocellulose. Taken together these results indicate that the core enzyme subunits are loosely associated in the premature core. The temperature-dependent maturation is required for the core subunits to be tightly associated, leading to the formation of structurally stable and functionally active RNA polymerase.