Structural analysis and assembly pathway of the pathogenic bacterial type IVB secretion system transport channel

2015 Fiscal Year Final Research Report

• Project/Area Number: 25460530
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Bacteriology (including mycology)
• Research Institution: Osaka University
• Principal Investigator: Kubori Tomoko 大阪大学, 微生物病研究所, 特任講師(常勤) (20397657)
• Co-Investigator(Renkei-kenkyūsha): IMADA Katsumi 大阪大学, 理学部, 教授 (40346143) ; Koike Masafumi 大阪大学, 微生物病研究所, 特任研究員(常勤) (50639979)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 細菌 / タンパク質複合体 / 感染症 / 分泌系 / レジオネラ / 病原性

Outline of Final Research Achievements

The bacterial pathogen Legionella pneumophila delivers a large array of the effector proteins into infected host cells using the type IVB secretion system. Among the proteins composing the system, inner membrane proteins DotI and DotJ form a hetero subcomplex that is anticipated to work as a transport channel of the IVB secretion system. We solved the crystal structure of the periplasmic domain of DotI and conducted functional analyses using the structural information. Bacterial localization analyses suggested that the DotI/DotJ complex can associate with the core complex of the type IVB secrestion system on demand. In addition, we identified a bacterial ATPase that associates with the DotI/DotJ complex and is essential for the secretion function. These findings support our hypothesis that the DotI/DotJ complex plays a role crucial for the IVB secretion utilizing the ATP energy.

Free Research Field

細菌学