Elucidation of the life-sustaining mechanism of hyperthermophilic archaea without DNA replication origin

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K22289
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 38:Agricultural chemistry and related fields
• Research Institution: Kyushu University
• Principal Investigator: Ishino Yoshizumi 九州大学, 農学研究院, 教授 (30346837)
• Co-Investigator(Kenkyū-buntansha): 松見 理恵 九州大学, 農学研究院, 准教授 (90397597)
• Project Period (FY): 2019-06-28 – 2022-03-31
• Keywords: アーキア / DNA複製 / 複製起点 / 超好熱菌 / DNA組換え

Outline of Final Research Achievements

Mutant strains, lacking the oriC and adjacent orc1/cdc6 gene, respectively, were isolated from Thermococcus kodakarensis, which is located at the root of the phylogenetic tree. and they were shown to grow almost in the same manner as the wild type strain. Since the ATPase activity of the purified Orc1/Cdc6 was suppressed in an oriC-dependent manner, it was considered that Orc1/Cdc6 binds to oriC as an ATP-form and turns on the switch to start DNA replication. The activity of Orc1/Cdc6 to unwind the double strand of the oriC region has not been detected, but the oriC-deficient mutant shows an increase in RadA production, andwe expect T. kodakarensis uses oriC-dependent and independent DNA replication modes properly.

Free Research Field

分子生物学

Academic Significance and Societal Importance of the Research Achievements

本研究は、生命の維持に必須のDNA複製起点 (oriC) がゲノム上に存在しなくても生き続ける超好熱性の生物が、どのように生命を維持しているのかを解明することによって、現在の我々の細胞で怒っている生命維持装置がどのように生まれ進化していきたのかを理解することができると考えて行ったもので、未だ解明には至っていないが、着実に研究は進み、我々の理解は深まった。