对翻译启动因子2的晶体包装分析揭示了其功能的新细节
O S Nikonov1, E Y Nikonova1, N V Lekontseva1
1Institute of Protein Research, Institutskaya 4, 142290 Pushchino, Moscow Region, Russian Federation.
Acta crystallographica. Section D, Structural biology
|June 11, 2024
概括
翻译启动因子2 (eIF2) 将 metionyl-tRNA 传递给核糖体. 对Sulfolobus solfataricus eIF2的晶体分析揭示了其功能机制和调节的洞察力.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 生物化学 生化学
背景情况:
- 翻译启动因子2 (eIF2) 对于真核生物和古生物的蛋白质合成至关重要.
- eIF2与GTP和启动器tRNA形成复合体,将其传递到小核糖体子单元.
- 了解eIF2的结构和功能是解读翻译启动法规的关键.
研究的目的:
- 为了研究翻译启动因子2 (eIF2) 函数的结构基础.
- 为了分析来自Sulfolobus solfataricus的结晶eIF2的分子包装.
- 阐明核酸结合口袋元件和功能开关在eIF2调节中的作用.
主要方法:
- 在十个不同的空间组中,eIF2及其子单位从Sulfolobus solfataricus结晶.
- 在获得的晶体结构中分析分子包装.
- 基于晶体学数据的结构功能关系研究.
主要成果:
- 在20年内获得了Sulfolobus solfataricus eIF2的多种晶体形式.
- 对分子包装的分析为eIF2.2的结构组织提供了洞察力.
- 该研究确定了核酸结合口袋和功能开关中的关键元素.
结论:
- 结构数据阐明了eIF2与GTP和tRNA相互作用的机制.
- 了解分子包装有助于理解外部因素如何影响eIF2活动.
- 这项工作增强了我们对古生物和真核生物的翻译启动调节知识.
相关概念视频
Initiation of Translation
32.5K
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
32.5K
Improving Translational Accuracy
10.1K
Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in...
10.1K
Leaky Scanning
5.1K
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R...
5.1K
Termination of Translation
25.4K
The large ribosomal subunit has several important structures essential to translation. These include the peptidyl transferase center (PTC) - which is the site where the peptide bond is formed - and a large, internal, water-filled tube through which the nascent polypeptide moves. This latter structure is called the Peptide Exit Tunnel, and it begins at the PTC and spans the body of the large ribosomal subunit. During translation, as the nascent polypeptide chain is synthesized, it passes through...
25.4K
Transcription Initiation
16.4K
Initiation is the first step of transcription in eukaryotes. Prokaryotic RNA Polymerase (RNAP) can bind to the template DNA and start transcribing. On the other hand, transcription in eukaryotes requires additional proteins, called transcription factors, to first bind to the promoter region in the DNA template. This binding helps recruit the specific RNAP that can assemble on the DNA and start transcription.
The promoters and enhancers and their accessory proteins allow tight regulation of...
The promoters and enhancers and their accessory proteins allow tight regulation of...
16.4K
Cotranslational Protein Translocation
7.3K
Translocation of proteins across membranes is an ancient process that occurs even in bacteria and archaebacteria. In fact, the components of the translocation machinery are still conserved between prokaryotes and eukaryotes.
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
7.3K


