Subunits of RNA polymerase in function and structure. VI. Sequence of the assembly in vitro of Escherichia coli RNA polymerase.
Subunits of RNA polymerase in function and structure. VI. Sequence of the assembly in vitro of Escherichia coli RNA polymerase.
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RNA聚合酶亚基的功能和结构。
DOI：
10.1016/0022-2836(76)90125-x
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发表时间：
1976
影响因子：
5.6
通讯作者：
A. Ishihama
中科院分区：
文献类型：
--
作者：
T. Saitoh;A. Ishihama
对大肠杆菌RNA聚合酶体外组装的详细分析表明，核心酶亚基的组装顺序为：2 α→α 2→β α 2 β→β ' α 2 ββ '（过早核心）→E（活性核心）。作为该序列的限速步骤，早核酶的激活可以通过三种不同的方式实现：自我再激活、σ亚基（σ或σ '）促进的再激活和dna促进的再激活。尽管关于sigma亚基或DNA对核心酶成熟的促进作用一直存在分歧，但目前的发现解决了这一分歧，即在高浓度盐或甘油存在的情况下，单独的过早核心可以被激活，而在体内盐浓度低的情况下，sigma亚基或DNA需要最大程度的激活。然而，这三种方式中的哪一种在RNA聚合酶的体内形成过程中起作用仍未得到解决。
Detailed analysis of the assembly in vitro of Escherichia coli RNA polymerase reveals that core enzyme subunits are assembled in the following sequence: 2 α→ α 2→ β α 2 β→ β′ α 2 ββ′(premature core)→ E (active core). Activation of the premature core enzyme, the rate-limiting step in this sequence, can be achieved in three different ways: self-reactivation, sigma subunit (σ or σ′)-promoted reactivation, and DNA-promoted reactivation. Although there has been disagreement on the enhancement of core enzyme maturation by sigma subunit or DNA, the discrepancy is resolved by the present finding that the premature core alone can be activated in the presence of high concentrations of salt or glycerol, whereas at a salt concentration as low as that in vivo, sigma subunit or DNA is required for maximum activation. However, the question remains unsolved as to which of the three ways operates in the in vivo process of RNA polymerase formation.