XPB (xeroderma pigmentosum type B) is an ATP-dependent DNA helicase in humans that is a part of the TFIIH transcription factor complex.

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2011年1月30日 · We report that triptolide covalently binds to human XPB (also known as ERCC3), a subunit of the transcription factor TFIIH, and inhibits its DNA-dependent ATPase activity, which leads to the...

核苷酸切除修复 （nucleotide excision repair, NER）是一种修复由紫外线和 化学致癌物 引起的各种DNA损伤的重要机制。 许多被 诊断 为着色性干皮病（xeroderma pigmentosum, XP）的患者在编码参与NER机制的蛋白的基因之一中存在突变。 众所周知，这些患者对紫外线引起的皮肤癌的高易感性是由于NER功能的缺乏。 这也告诉我们，NER是对癌症的一种防御。 NER的第一步涉及 XPC蛋白，它是多种XP致病性基因产物之一，它作为一种“传感蛋白”起作用，用于确定DNA结 …

2012年5月10日 · Mutations in three subunits of TFIIH (XPB, XPD and p8) give rise to the autosomal recessive disorders xeroderma pigmentosum (which is sometimes associated with Cockayne syndrome) and...

XPB是TFIIH核心的ATP依赖的DNA转移酶亚基，在启动子melting，启动子逃逸及转录启动中起作用。 CAK由CDK7，细胞周期蛋白H（CycH）和MAT1形成。 CDK7激酶使Pol II C末端结构域（CTD）磷酸化。

2015年3月1日 · XPB is an essential core subunit of the eukaryotic basal transcription factor complex TFIIH which plays a dual role in transcription and DNA repair: 1) to facilitate the melting of the promoter during the initiation of RNA polymerase II transcription; 2) to unwind double stranded DNA (dsDNA) around a DNA lesion during nucleotide excision repair ...

2006年4月21日 · Helicases are molecular motors known to unwind double-stranded DNA. In a recent issue of Molecular Cell, Fan et al. (2006) revealed the core structure of XPB helicase, a component of transcription factor IIH, and proposed a mechanism for its dual role in transcription and nucleotide excision repair.

Here, we determined crystal structures of an Archaeoglobus fulgidus XPB homolog (AfXPB) that characterize two RecA-like XPB helicase domains and discover a DNA damage recognition domain (DRD), a unique RED motif, a flexible thumb motif (ThM), and implied conformational changes within a conserved functional core.

XPB is an essential core subunit of the eukaryotic basal transcription factor complex TFIIH which plays a dual role in transcription and DNA repair: 1) to facilitate the melting of the promoter during the initiation of RNA polymerase II transcription; 2) to unwind double stranded DNA (dsDNA) around a DNA lesion during nucleotide excision repair ...