Study of functional interplay of tRNA mimicry proteins and translational GTPase proteins.

2015 Fiscal Year Final Research Report

• Project/Area Number: 25291020
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Functional biochemistry
• Research Institution: The University of Tokyo
• Principal Investigator: Ito Koichi 東京大学, 新領域創成科学研究科, 教授 (10262073)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: リボソーム / 翻訳制御 / 遺伝暗号 / 直行性 / タンパク質合成 / tRNA擬態タンパク質 / 翻訳終結 / mRNA品質管理

Outline of Final Research Achievements

We performed genetic mapping and analyses of critical sites that contribute to functional complementation with exceptionally nonfunctional heterologous eRF3 in yeast, and clarified the functional interplay among the tRNA mimic eRF1, its carrier protein eRF3 and ribosome.
To elucidate the molecular roles of this residue in codon discrimination, we conducted systematic mutagenesis of 123rd amino acid and applied to stop codon specificity analyses in vivo. We found that a simple rule could explain sub-specific patterns of 123th residues in codon discrimination, and that the residue contributed to functional coupling with eRF3, suggesting that the 123th residue is a novel class of functional residue. Furthermore, our structural modeling of eRF1 in the quasi-A/T state also suggested a distinctive role for the 123th residue in the putative molecular interplays on the ribosomal decoding site. We also proposed a model for the putative role of the 123th residue in stop codon discrimination.

Free Research Field

分子生物学