Elucidation of the bacterial adaptive immune system of extremely thermophilic bacterium by high-resolution structural studies
Project/Area Number |
16K07285
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Structural biochemistry
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Research Institution | Institute of Physical and Chemical Research |
Principal Investigator |
Shinkai Akeo 国立研究開発法人理化学研究所, 開拓研究本部, 先任研究員 (10391989)
|
Project Period (FY) |
2016-04-01 – 2020-03-31
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Project Status |
Completed (Fiscal Year 2019)
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Budget Amount *help |
¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2018: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2016: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
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Keywords | CRISPR-Cas / Cmr複合体 / 超分子複合体 / リボヌクレオタンパク質 / リボヌクレアーゼ / 低分子RNA / 無細胞タンパク質合成法 / 構造生物学 / 機能未知タンパク質 / 細菌 |
Outline of Final Research Achievements |
CRISPR-Cas system is a bacterial adaptive immune system, which degrade foreign DNA or RNA such as that derived from virus. Cmr complex, which is composed of six proteins (Cmr1~Cmr6) and a small RNA (crRNA), is one of the components of the CRISPR-Cas. The Cmr complex cleaves the single strand RNA complementary to the crRNA. The Cmr complex derived from extremely thermophilic bacterium Thermus thermophilus, and the two mutant complexes, which lacks Cmr1 or Cmr5, were constructed in vitro by using E. coli cell free protein synthesis method, and then, their structures and RNase activities were investigated. We found that RNase activity of the Cmr complex was increased by lacking Cmr1. Without Cmr5, structure of the Cmr complex become unstable and the target RNA was irregularly cleaved. Thus, the Cmr1 and Cmr5 play roles in controlling the RNase activity of the Cmr complex.
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Academic Significance and Societal Importance of the Research Achievements |
CRISPR-Cas系は多くの細菌が持つ獲得免疫系で、細胞へ侵入してくるウイルスなどのDNAやRNAを分解する装置である。CRISPR-Cas系はヒトなどの高等生物が持つ獲得免疫システムの原型とも考えられるので、本システムの作用機構を解明することは獲得免疫システムの進化を考察する際に重要である。CRISPR-Casシステムを構成しているCmr複合体は6種類のタンパク質と1種類の低分子RNAからなる超分子複合体で、一本鎖RNAを分解する活性を持つ。Cmr複合体の構造形成や活性発現において複合体を構成している蛋白質がどのように機能しているのかを明らかにすることは、蛋白質科学的にも重要である。
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Report
(5 results)
Research Products
(2 results)