Structure analysis of multi-factor complex of eukaryotic translation initiation factor

真核翻译起始因子多因子复合物的结构分析

• 批准号: 16570089
• 负责人: YAO Min
• 金额: $ 2.5万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16570089/
• 关键词: Translation; Translation initiation; Translation initiation factors; eIF; Initial tRNA; GTP加水分解; 立体構造; X線結晶構造解析

For all living organisms, the regulation of gene expression is an important control mechanism in their biological processes such as environmental adaptation, development, and differentiation. The translation is the final step in the flow of the gene expression, and it can be divided into three distinct phases : initiation, elongation and termination. Initiation is most complex of these phases and involves greatest number of regulatory processes that all performed by more than 30 factors (eIFs) and ribosome. The regulation at this phase allows for immediate and rapid response to cellular stress (starvation, heat shock, virus infection) or apoptosis, and controls the cellular activity level in their biological processes such as memory, development, and differentiation. The fundamental processes in translation initiation are the assembling components of eIF1, eIF2-GTP, eIF3, eIF5, and Met-tRNA^i to a multi-factor complex (MFC), binding MFC to ribosomal small subunit (43S) and then binding … More 5'end of mRNA to 43S, and scanning mRNA to recognize the start codon on the resulting 48S complex. In this study, the functional and structural analysis of MFC mainly on eIF2 was focused. Especially, conformation changes and interaction of the components during assemble were analyzed for understanding the reaction mechanism and regulation of translation initiation. Last year, we have solved the structures of a/eIF2βγ and a/eIF2βγ-GDP complex. Based on the obtained structures the functional analysis of a/eIF2βγ was carried out this year.Considering the structural and functional homology between a/eIF2γ and translation elongation factor EF-Tu, switch1 motif of a/eIF2γ may play an important role in binding and releasing Met-tRNA^i similarly to that of EF-Tu. In this study, the obtained structure of a/eIF2βγ-GDP complex showed that a/eIF2β was interacted with switch1 motif of a/eIF2βγ and consequently switch1 motif was positioned in the distant from GDP-binding site. Moreover, conformation changes of switch1 region between the structures of a/eIF2βγ and a/eIF2βγ-GDP, and a/eIF2βγ and a/eIF2γ were found. Therefore, we mutated conserved residues of switch1 motif, and inspected the effect of these mutations on Met-tRNA^i binding. The paper was in submitted. Less

对于所有生物体，基因表达的调节是其生物过程如环境适应、发育和分化的重要控制机制。翻译是基因表达流程的最后一步，它可以分为三个不同的阶段：起始，延伸和终止。起始是这些阶段中最复杂的，涉及最多的调节过程，全部由30多种因子（eIF）和核糖体执行。该阶段的调节允许对细胞应激（饥饿、热休克、病毒感染）或凋亡的立即和快速反应，并控制其生物学过程如记忆、发育和分化中的细胞活性水平。翻译起始的基本过程是eIF 1、eIF 2-GTP、eIF 3、eIF 5和Met-tRNA^i组装成多因子复合物（MFC），将MFC结合到核糖体小亚基（43 S），然后结合 ...更多信息 将mRNA的5 '末端连接到43 S，并扫描mRNA以识别所得48 S复合物上的起始密码子。本研究以eIF 2为研究对象，对MFC的功能和结构进行了分析。特别是对组装过程中各组分的构象变化和相互作用进行了分析，以了解翻译起始的反应机理和调控。去年，我们已经解决了a/eIF 2 βγ和a/eIF 2 βγ-GDP复合物的结构。基于所获得的结构，本年度对a/eIF 2 βγ进行了功能分析，考虑到a/eIF 2 γ与翻译延伸因子EF-Tu在结构和功能上的同源性，a/eIF 2 γ的switch 1基序可能与EF-Tu类似，在结合和释放Met-tRNA^i中起重要作用。本研究中，a/eIF 2 βγ-GDP复合物的结构表明，a/eIF 2 β与a/eIF 2 βγ的开关1基序相互作用，因此开关1基序位于远离GDP结合位点的位置。此外，发现a/eIF 2 βγ与a/eIF 2 βγ-GDP、a/eIF 2 βγ与a/eIF 2 γ结构之间存在switch 1区的构象变化，因此，我们对switch 1基序的保守残基进行了突变，并考察了这些突变对Met-tRNA^i结合的影响。论文已提交。少

项目成果

Crystal structure of the putative RNA methyltransferase PH1948 from Pyrococcus horikoshii, in complex with the copurified S-adenosyl-L-homocysteine

来自堀越火球菌的假定 RNA 甲基转移酶 PH1948 的晶体结构，与共纯化的 S-腺苷-L-高半胱氨酸复合物

• 发表时间: 2005
• 期刊: Proteins : Structure, Function, and Bioinformatics 61
• 作者: Katsuhiko Sato;Kazuo Yamasaki;Takashi Daiho;Yuki Miyauchi;Hidetoshi Takahashi;Akemi Ishida-Yamamoto;Satoshi Nakamura;Hajime Iizuka;Hiroshi Suzuki;M.Sokabe;M.Yao;Y-G.Gao
• 通讯作者: Y-G.Gao

Crystal structure of the regulatory subunit of archaeal initiation factor 2B (aIF2B) from hyperthermophilic archaeon Pyrococcus horikoshii OT3:: a proposed structure of the regulatory subcomplex of eukaryotic IF2B

• DOI: 10.1016/j.bbrc.2004.05.045
• 发表时间: 2004-07-02
• 期刊: BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
• 影响因子: 3.1
• 作者: Kakuta, Y;Tahara, M;Kimura, M
• 通讯作者: Kimura, M

Molecular basis of alanine discrimination in editing site

编辑位点丙氨酸歧视的分子基础

• 发表时间: 2005
• 期刊: Proc. Natl. Adad. Sci. USA 102
• 作者: Katsuhiko Sato;Kazuo Yamasaki;Takashi Daiho;Yuki Miyauchi;Hidetoshi Takahashi;Akemi Ishida-Yamamoto;Satoshi Nakamura;Hajime Iizuka;Hiroshi Suzuki;M.Sokabe
• 通讯作者: M.Sokabe

Structure of the type I L-asparaginase from the hyperthermophilic archaea Pyrococcus horikoshii at 2.16 A resolution

来自超嗜热古菌堀越火球菌的 I 型 L-天冬酰胺酶的结构，分辨率为 2.16 A

• 发表时间: 2005
• 期刊: Acta Crystallographic Section D 61
• 作者: Katsuhiko Sato;Kazuo Yamasaki;Takashi Daiho;Yuki Miyauchi;Hidetoshi Takahashi;Akemi Ishida-Yamamoto;Satoshi Nakamura;Hajime Iizuka;Hiroshi Suzuki;M.Sokabe;M.Yao
• 通讯作者: M.Yao