title: Domain-based biophysical characterization of the structural and thermal stability of FliG, an essential rotor component of the Na+-driven flagellar motor.
abstract: Many bacteria move using their flagellar motor, which generates torque through the interaction between the stator and rotor. The most important component of the rotor for torque generation is FliG. FliG consists of three domains: FliGN, FliGM, and FliGC. FliGCcontains a site(s) that interacts with the stator. In this study, we examined the physical properties of three FliG constructs, FliGFull, FliGMC, and FliGC, derived from sodium-driven polar flagella of marineVibrio. Size exclusion chromatography revealed that FliG changes conformational states under two different pH conditions. Circular dichroism spectroscopy also revealed that the contents of α-helices in FliG slightly changed under these pH conditions. Furthermore, we examined the thermal stability of the FliG constructs using differential scanning calorimetry. Based on the results, we speculate that each domain of FliG denatures independently. This study provides basic information on the biophysical characteristics of FliG, a component of the flagellar motor.
authors.affiliation: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Onoue
authors.affiliation: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan.
authors.forename: Rei
authors.initials: R
authors.lastname: Abe-Yoshizumi
authors.affiliation: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan.
authors.forename: Mizuki
authors.initials: M
authors.lastname: Gohara
authors.affiliation: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan.
authors.forename: Yuuki
authors.initials: Y
authors.lastname: Nishino
authors.affiliation: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan.
authors.forename: Shiori
authors.initials: S
authors.lastname: Kobayashi
authors.affiliation: TA Instruments Japan Inc., Gotanda, Shinagawa-ku, Tokyo 141-0031, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Asami
authors.affiliation: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan.
authors.forename: Michio
authors.initials: M
authors.lastname: Homma
keywords: DSC; FliG; flagellar motor; rotor