Protein evolution from simple peptide to versatile protein fold

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K15854
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 45020:Evolutionary biology-related
• Research Institution: Waseda University (2023); Institute of Physical and Chemical Research (2020-2022)
• Principal Investigator: Yagi Sota 早稲田大学, 人間科学学術院, 講師(任期付) (10779820)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: タンパク質 / 生命の起源 / RNAポリメラーゼ

Outline of Final Research Achievements

In this project, I have succeeded in experimentally reconstruction of the evolution of the β-barrel structure conserved in many proteins involved in the gene expression system. First, I found that the β-barrel fold DPBB conserved in the active core of RNA polymerase can be reconstituted from a short dimeric peptide of about 40 residues consisting of seven types of amino acids. I also found that this simple short peptide can adopt a new β-barrel structure, DZBB, which is not found in nature. The DZBB can be converted to other β-barrel protein folds, such as the OB structure, suggesting that it may be the missing-link in the evolution of proteins. These findings are a remarkable achievement in elucidating the early evolution of gene expression systems.

Free Research Field

分子進化学

Academic Significance and Societal Importance of the Research Achievements

タンパク質の初期進化研究は理論的研究が先行しており、実験的検証が進んでいない状況であった。それに対して、本研究では、遺伝子発現系に関与するRNAポリメラーゼやリボソームタンパク質が持つβバレルタンパク質がどのようにして単純なペプチド配列から進化してきたのか、またβバレル構造の多様化が生じてきたのかを実験的に明らかにしてきた。これらの結果は、将来的に遺伝子発現系がどのように誕生し進化をしてきたかを明らかにする上で実験的な証拠を提供し、生命の起源の理解に大きな貢献が期待できる。