Expression, purification and biochemical characterization of the cytoplasmic loop of PomA, a stator component of the Na⁺ driven flagellar motor

• Yoshizumi Rei Abe

  Division of Biological Science, Graduate School of Science, Nagoya University

• Kobayashi Shiori

  Division of Biological Science, Graduate School of Science, Nagoya University

• Gohara Mizuki

  Division of Biological Science, Graduate School of Science, Nagoya University

• Hayashi Kokoro

  Laboratory of Biophysics, Graduate School of Biological Sciences, Nara Institute of Science and Technology

• Kojima Chojiro

  Laboratory of Biophysics, Graduate School of Biological Sciences, Nara Institute of Science and Technology

• Kojima Seiji

  Division of Biological Science, Graduate School of Science, Nagoya University

• Sudo Yuki

  Division of Biological Science, Graduate School of Science, Nagoya University

• Asami Yasuo

  TA Instruments Japan, Inc.

• Homma Michio

  Division of Biological Science, Graduate School of Science, Nagoya University

Abstract

Flagellar motors embedded in bacterial membranes are molecular machines powered by specific ion flows. Each motor is composed of a stator and a rotor and the interactions of those components are believed to generate the torque. Na⁺ influx through the PomA/PomB stator complex of Vibrio alginolyticus is coupled to torque generation and is speculated to trigger structural changes in the cytoplasmic domain of PomA that interacts with a rotor protein in the C-ring, FliG, to drive the rotation. In this study, we tried to overproduce the cytoplasmic loop of PomA (PomA-Loop), but it was insoluble. Thus, we made a fusion protein with a small soluble tag (GB1) which allowed us to express and characterize the recombinant protein. The structure of the PomA-Loop seems to be very elongated or has a loose tertiary structure. When the PomA-Loop protein was produced in E. coli, a slight dominant effect was observed on motility. We conclude that the cytoplasmic loop alone retains a certain function.<br>

Journal

• BIOPHYSICS

  BIOPHYSICS 9 (0), 21-29, 2013

  The Biophysical Society of Japan

Keywords

• bacterial flagellum
• ion-driven motor
• protein interaction
• stator

Details

• CRID: 1390001205222085760
• NII Article ID: 130003366026
• DOI: 10.2142/biophysics.9.21
• ISSN: 13492942
• Web Site: https://www.jstage.jst.go.jp/article/biophysics/9/0/9_21/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed