Molecular mechanism of the regulation of biosynthesis of polyamine which is covalently bound to the peptidolycan by the ribosomal protein L10 in bacteria

2016 Fiscal Year Final Research Report

• Project/Area Number: 26292043
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Applied microbiology
• Research Institution: Shokei Gakuin College
• Principal Investigator: Kamio Yoshiyuki 尚絅学院大学, 総合人間科学部, 名誉教授 (00109175)
• Co-Investigator(Kenkyū-buntansha): 金子 淳 東北大学, (連合)農学研究科(研究院), 准教授 (30221188) ; 姚 閔 北海道大学, 先端生命科学研究科(研究院), 教授 (40311518) ; 児島 征司 東北大学, 学内共同利用施設等, 助教 (20745111) ; 草野 友延 東北大学, 生命科学研究科, 教授 (40186383)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: ポリアミン合成制御機構 / ペプチドグリカン結合型ポリアミン / バクテリアアンチザイムＬ－１０ / Selenomonas ruminantium / 外膜主要たんぱく質Ｍｅｐ４５ / リピド中間体：ポリアミン転移酵素Ltd / ClpXP protease

Outline of Final Research Achievements

In Selenomonas ruminantium, cadaverine serves as an essential constituent of the peptidoglycan for the maintenance of envelope integrity through the interaction with SLH domain of Mep45, the outer membrane protein. Cytoplasmic biosynthesis of cadaverine occurs totally in a eukaryotic-like manner. Lysine/ornithine decarboxylase (LDC/ODC), responsible for cadaverine synthesis in this bacterium, displays significant homology to the eukaryotic ODC, and its activity is tightly regulated by antizyme(L10)-mediated proteolysis. Here, we show the following 4 findings, i.e. (i) Determination of the complete genome sequence of S. ruminantium, (ii) Molecular mechanism of Mep45 function. We found that Mep45 forms a non-specific diffusion channel in its C-terminal region, (iii)Identification of the ATP-dependent ClpX/P for degradation of LDC/ODC, which is mediated by L-10 and (iv) Identification of an enzyme for cadaverine-adding reaction into the peptidoglycan of this bacterium.

Free Research Field

微生物生理学