翻译启动因子eIF-2的β子单元的结构
V K Pathak1, P J Nielsen, H Trachsel
1Department of Biological Chemistry, School of Medicine, University of California, Davis 95616.
Cell
|August 26, 1988
概括
研究人员确定了一个用于蛋白质合成启动因子2β (eIF-2β) 的人类基因. 这种对翻译至关重要的蛋白质具有结构特征,表明RNA相互作用和与酵母蛋白的功能相似性.
科学领域:
- 分子生物学分子生物学
- 遗传学 遗传学是一种遗传学.
- 蛋白质生物化学 蛋白质生物化学
背景情况:
- 蛋白质合成是一个由启动因子调节的基本细胞过程.
- 蛋白质合成启动因子2 (eIF-2) 在速度限制的翻译步骤中起着关键作用.
- 了解eIF-2子单元的结构和功能是解读翻译控制的关键.
研究的目的:
- 隔离和鉴定编码eIF-2β子单元的人类cDNA的特征.
- 研究人类eIF-2β蛋白的结构和功能性质.
- 为了比较人类eIF-2β与已知的功能域和相关蛋白质.
主要方法:
- 人类肝脏cDNA库查和测序.
- 从cDNA转录中进行eIF-2β的体外合成.
- 分析蛋白质序列的保存图案 (GTP结合部位,指,聚氨酸块).
- 人类eIF-2β序列与酵母蛋白 Sui3.3 的比较.
主要成果:
- 一个编码为eIF-2β (333氨基酸,38,404大) 的1416bp人类cDNA被成功分离和测序.
- 合成的eIF-2β被纳入内源子eIF-2复合物中,证实了它的功能.
- 该蛋白质含有假定的GTP结合点,指图案,以及带有聚氨酸块的充电N终端区域,表明具有RNA结合能力.
- 在人类eIF-2β和酵母Sui3之间发现了显著的序列一致性,特别是在聚氨酸和指域中.
结论:
- 人类eIF-2β子单元具有表明RNA相互作用的结构特征,并在翻译启动中发挥作用.
- 已识别的结构图案是保存的,并且可能对eIF-2β活性具有重要功能.
- 与酵母Sui3的同质性支持这些域在调节蛋白质合成中的功能意义.
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Ribosomes
Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that synthesize large quantities of protein—such as secretory cells in the human pancreas—can contain millions of ribosomes.
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within...
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