Regulation of insertion sequnces found in the genome of Bacillus subtilis (natto)

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K07683
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Applied microbiology
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: KIMURA Keitarou 国立研究開発法人農業・食品産業技術総合研究機構, 食品研究部門, ユニット長 (20353980)
• Research Collaborator: YOSHIKAWA Hirofumi
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 挿入配列 / ゲノム進化 / 納豆菌 / 転移 / 遺伝子破壊 / insertion sequnce / transposition / IS256Bsu1

Outline of Final Research Achievements

Insertion sequence (IS) is a mobile genetic element consist of a transposase gene and an inverted repeat sequence. ISs translocate in the genome and can disrupt gene(s), thus have committed on structural evolution of genome. This study started to elucidate regulatory mechanism of ISs found in the genome of Bacillus subtilis (natto).
On of the most important findings obtained in this study is suppressive function of the gene BSNT_10618. Disruption of BSNT_10618 greatly increased the frequency of transposition of the insertion sequence which suggested that Bacillus subtilis (natto) can harbor many copies of IS by suppressing the translocation of IS with the BSNT_10618.

Free Research Field

応用微生物学

Academic Significance and Societal Importance of the Research Achievements

挿入配列（以下、IS)の発現制御に関する先行研究として，大腸菌で見つかったIS転移促進タンパク質Ieeが挙げられる．本研究では，Ieeと部分的な類似性を持つ納豆菌BSNT_10618が，むしろ転移を抑制する機能を持つことが明らかになった．納豆菌のように非常に多種多コピーのISを有する株が転移を抑制する仕組みを持つ可能性が強く示唆されたことに学術的意義がある．また，RNS-seq解析（DNA配列解析装置による網羅的な遺伝子発現解析）を通じて，東京農大が開発したIS転移頻度測定法（Jumping CAT法）の再現性と妥当性が確認できたことは科学的に意義深く，継続的な研究深化に繋がる成果である.