Systematic understanding of novel anti-virus system in a cell

2015 Fiscal Year Final Research Report

• Project/Area Number: 25440013
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Molecular biology
• 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, 横山構造生物学研究室, 先任研究員 (10391989)
• Co-Investigator(Renkei-kenkyūsha): AGARI Yoshihiro 国立研究開発法人理化学研究所, 放射光科学総合研究センター, 特別研究員 (50469889)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: CRISPR-Cas / 獲得免疫 / 超分子複合体 / 電子顕微鏡構造 / タンパク質 / 低分子RNA / リボヌクレアーゼ / Thermus thermophilus

Outline of Final Research Achievements

CRISPR-Cas system is a bacterial adaptive immune system, which degrades foreign DNA or RNA such as that derived from virus. We selected a thermophilic bacterium, Thermus thermophilus, which has several CRISPR-Cas systems, for a model organism to study their systematic manner in a cell. We investigated structure and function of two large complexes comprising two CRISPR-Cas systems of the strain. We found that each complex was composed of several protein subunits and a small RNA molecule, and adopted a helical structure. Nucleotide sequences of the small RNA molecules are similar to each other. Both complexes degraded single-strand RNA in a similar manner. These results suggest that the two complexes have been evolved from a common ancestor, and that they comprise backup system in a cell to respond to virus infection.

Free Research Field

分子生物学