**Room changed to Lab 5 D23**

This seminar is aimed at researchers and students with a background in the fields of life sciences, mathematics, and physics. If you are interested in the topic please join the seminar and discuss.

Speaker: Shinichi Aizawa

Title: Two Mysteries of the Bacterial Flagellum: The Simplest Filament and the Most Complicated Rotary Motor

Abstract: Bacteria swim in liquid by means of flagella. The majority of the flagellar structure is a helical filament, which rotates by the tiny motor at the base, the flagellar motor. The motor contains four rings and a rod penetrating the rings. The energy of rotation is the proton motive force through the membrane. However, the mechanism of rotation is not understood, that is, what is the principle of energy conversion from proton flow to mechanical rotation? The flagellar filament is tubular helix made from a single kind of protein, flagellin. The filament is assumed to be as strong as a piano wire to give a propulsion force in water. The mechanism why the chemically-identical flagellin molecules polymerize into a helical shape has been not unveiled. The both questions require theoretical speculations to solve, because the structures have been solved at the atomic level.

Profile: Shinichi Aizawa is Professor Emeritus at the Prefectural University of Hiroshima currently visiting OIST through the Visiting Program (TSVP). He is considered one of the world’s foremost experts in the structure and function of bacterial flagella. His contributions to solving flagellar polymorphism are very highly regarded, and his book “The Flagellar World” has become a standard textbook in the field. After studying at Tohoku and Nagoya Universities in Japan, he spent several years as a Postdoc at Yale University. His long career in academia included positions at Research & Development Corporation of Japan (now JST) in Tsukuba, Teikyo University, University of Hawaii, Flinders University in Australia, and Martin-Luther University Halle in Germany.