在TFIID的TAF(II) 250子单元中,氨酸转移酶具有氨酸转移酶活性
C A Mizzen1, X J Yang, T Kokubo
1Department of Biology, University of Rochester, New York 14627, USA.
Cell
|December 27, 1996
概括
转录因子TFIID含有TAF(II) 蛋白质,具有氨酸转移酶 (HAT) 活性. 这种HAT活动可能有助于TFIID在转录启动过程中访问抑制的染色质.
科学领域:
- 分子生物学分子生物学
- 基因规则 基因规则
- 生物化学 生物化学
背景情况:
- 转录启动因子TFIID是TATA盒结合蛋白 (TBP) 和TBP相关因子 (TAF) 的复合体.
- TAF (II) 作为辅因子起作用,通过与特定激活剂相互作用,促进激活转录.
研究的目的:
- 研究人类TAF(II) 250及其在Drosophila和酵母中的同类的酶活性.
- 为了确定TAF(II) 蛋白质是否具有组织酸转移酶 (HAT) 活性.
主要方法:
- 在体外试验中进行了测试,以评估人类TAF{II) 250的HAT活性,Drosophila dTAF{II) 230和酵母yTAF{II) 130.0.
- 在蛋白质结构中绘制了HAT活动的位置.
- 检查了HAT活性的基质特异性,使用histon H3和H4.4进行了检查.
主要成果:
- 人类TAF(II) 250及其在Drosophila和酵母中的同类在体外表现出素乙转移酶 (HAT) 活性.
- HAT活动局限于dTAF (II) 230和yTAF (II) 130.0.230的中央保护区域.
- dTAF (II) 230的HAT活性是特定于素H3和H4,类似于酵母和人类GCN5.5.
结论:
- TAF (II) 蛋白具有内在的氨酸转移酶 (HAT) 活性.
- 通过TAF(II) 250进行向性基因组乙化可能会促进TFIID获得转录抑制的染色质.
- 这一发现表明TFIID在转录启动期间的染色质重塑中发挥了新的作用.
相关概念视频
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01:30General Transcription Factors
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02:35Transcription Elongation Factors
Transcription elongation is a dynamic process that alters depending upon the sequence heterogeneity of the DNA being transcribed. Hence, it is not surprising that the elongation complex's composition also varies along the way while transcribing a gene.
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA into a...
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02:32Histone Modification
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...