Kumar Ananthanarayanan, Isumi Miyu, Sakuma Mayuko, Zhu Shiwei, Nishino Yuuki, Onoue Yasuhiro, Kojima Seiji, Miyanoiri Yohei, Imada Katsumi, Homma Michio
Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
Department of Macromolecular Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan.
J Biochem. 2017 Apr 1;161(4):331-337. doi: 10.1093/jb/mvw076.
The flagellar motor is embedded in the cell envelope and rotates upon interaction between the stator and the rotor. The rotation is powered by ion flow through the stator. A single transmembrane protein named FliL is associated with torque generation in the flagellar motor. We established an Escherichia coli over-expression system for FliL of Vibrio alginolyticus, a marine bacterium that has a sodium-driven polar flagellum. We successfully expressed, purified, and crystallized the ca. 17 kDa full-length FliL protein and generated a construct that expresses only the ca. 14 kDa periplasmic region of FliL (ΔTM FliL). Biochemical characterization and NMR analysis revealed that ΔTM FliL weakly interacted with itself to form an oligomer. We speculate that the observed dynamic interaction may be involved in the role of FliL in flagellar motor function.
鞭毛马达嵌入细胞包膜中，并在定子与转子相互作用时发生旋转。这种旋转由离子流经定子提供动力。一种名为FliL的单一跨膜蛋白与鞭毛马达中的扭矩产生相关。我们建立了一个用于表达嗜盐弧菌FliL的大肠杆菌过表达系统，嗜盐弧菌是一种具有钠驱动极鞭毛的海洋细菌。我们成功表达、纯化并结晶了约17 kDa的全长FliL蛋白，并构建了一个只表达约14 kDa FliL周质区域（ΔTM FliL）的构建体。生化特性分析和核磁共振分析表明，ΔTM FliL与自身发生微弱相互作用形成寡聚体。我们推测，观察到的动态相互作用可能与FliL在鞭毛马达功能中的作用有关。
