包含TAFII的复合体TFIID和TFTC的三维结构
概括
与TATA结合蛋白相关的因子 (TAF) 对于基因调节至关重要. 研究人员可视化了TFIID和TFTC复合物的结构,揭示了它们的分子结构和潜在的DNA结合能力.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 遗传学 是一个遗传学.
背景情况:
- 与TATA结合蛋白相关的因子 (TAF) 是转录因子复合体的重要组成部分.
- 这些复合体,包括TFIID和TFTC,通过RNA聚合酶II调节基因表达.
研究的目的:
- 为了确定TFIID和TFTC多蛋白复合体的高分辨率结构.
- 阐明它们在基因表达调节中的作用的结构基础.
主要方法:
- 电子显微镜被用来可视化这些复杂物.
- 单个粒子的数字图像分析被用来重建3.5纳米分辨率的结构.
主要成果:
- 人类TFIID的结构被揭示为一个具有四个球状域的宏分子.
- TFIID具有适合用于DNA结合的溶剂可访问槽.
- TFTC复合体比TFIID更大,包括五个域,其中四个结构类似于TFIID.
结论:
- 确定的结构为关键转录监管复合体的架构提供了洞察力.
- 这些发现表明TFIID的DNA相互作用机制.
- TFIID和TFTC之间的结构相似性可能表明在转录中具有共同的功能作用.
相关概念视频
Tail-anchoring of Proteins in the ER Membrane
Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins...
Total Internal Reflection Fluorescence Microscopy
Total internal reflection fluorescence microscopy or TIRF is an advanced microscopic technique used to visualize fluorophores in samples close to a solid surface with a higher refractive index, such as a glass coverslip. TIRF only allows fluorophores in proximity to the solid surface to be excited. When light from a medium with a lower refractive index (such as air) hits the glass coverslip at a critical angle, the light undergoes total internal reflection stead of passing through the glass.
Tandem Mass Spectrometry
Tandem mass spectrometry is a technique that uses multiple mass analyzers in series to obtain a higher selectivity and reduce chemical noise during analyte detection. Instruments with multiple analyzers separated by an interaction cell enable secondary fragmentation and selected study of the fragment ions.Secondary fragmentations occur in the interaction cell and can be induced by various factors. Fragmentation induced by collision with inert gases, such as N2, Ar, He, etc., is called...


