Function of Conserved Topological Regions within the Saccharomyces cerevisiae Basal Transcription Factor TFIIH.
Function of Conserved Topological Regions within the Saccharomyces cerevisiae Basal Transcription Factor TFIIH.
复制标题
酿酒酵母基础转录因子 TFIIH 内保守拓扑区域的功能。
DOI：
10.1128/mcb.00182-16
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发表时间：
2016
影响因子：
5.3
通讯作者：
Hahn,Steven
中科院分区：
文献类型：
--
作者：
Warfield,Linda;Luo,Jie;Ranish,Jeffrey;Hahn,Steven
TFIIH 是一种 10 亚基 RNA 聚合酶 II 基础转录因子，在 DNA 修复中具有双重作用。 TFIIH 包含三种酶功能和 30 多个保守子结构域和拓扑区域。我们系统地测试了三个 TFIIH 核心模块亚基（即 Ssl1、Tfb4 和 Tfb2）、DNA 易位酶亚基 Ssl2 和激酶模块亚基 Tfb3 中这些区域的功能。我们的结果与之前预测的 Tfb2 Hub、Ssl2 Lock 和 Tfb3 Latch 区域的作用一致，这些元件的突变通常在 TFIIH 亚基关联中具有严重缺陷。我们还发现了其他领域的意想不到的角色，这些领域的功能之前尚未定义。首先，Ssl1-Tfb4 环结构域对于 TFIIH 组装很重要。其次，Tfb2 Hub 和 HEAT 域与 Tfb3 相关，具有意想不到的作用。第三，Tfb3 环结构域对于与许多其他 TFIIH 亚基的关联非常重要。第四，Ssl1 N 端延伸 (NTE) 结构域的部分删除会抑制 TFIIH 功能，而不影响亚基关联。最后，我们使用位点特异性交联将 Tfb3 结合表面定位在 Rad3 Arch 结构域上。我们的交联结果表明 Tfb3 和 Rad3 具有不寻常的界面，Tfb3 结合在拱门的两个相对面上。
TFIIH is a 10-subunit RNA polymerase II basal transcription factor with a dual role in DNA repair. TFIIH contains three enzymatic functions and over 30 conserved subdomains and topological regions. We systematically tested the function of these regions in three TFIIH core module subunits, i.e., Ssl1, Tfb4, and Tfb2, in the DNA translocase subunit Ssl2, and in the kinase module subunit Tfb3. Our results are consistent with previously predicted roles for the Tfb2 Hub, Ssl2 Lock, and Tfb3 Latch regions, with mutations in these elements typically having severe defects in TFIIH subunit association. We also found unexpected roles for other domains whose function had not previously been defined. First, the Ssl1-Tfb4 Ring domains are important for TFIIH assembly. Second, the Tfb2 Hub and HEAT domains have an unexpected role in association with Tfb3. Third, the Tfb3 Ring domain is important for association with many other TFIIH subunits. Fourth, a partial deletion of the Ssl1 N-terminal extension (NTE) domain inhibits TFIIH function without affecting subunit association. Finally, we used site-specific cross-linking to localize the Tfb3-binding surface on the Rad3 Arch domain. Our cross-linking results suggest that Tfb3 and Rad3 have an unusual interface, with Tfb3 binding on two opposite faces of the Arch.