Dr. Fadel Samatey
Osaka University
Osaka, Japan

Friday, February 3, 2006
11:00 am (CT)
3269 Beckman Institute

Abstract

Bacteria swim by rotating long helical filaments called the flagellum. Each flagellum is rotated by a motor located at the base. The flagellum can be described as an assembly of 25 different proteins and can be divided in three substructures: the basal body, the hook and the filament. The filament, a long and relatively rigid structure, is made by the polymerization of thousands of copies of a single protein, FliC (51KDa), and functions as a propeller. The hook, a short and flexible filament, is made by the polymerization of about 130 molecules of FlgE (41 KDa) and functions as a universal joint. Major fragments of FliC and FlgE, called F41 and FlgE31, respectively, have been crystallized and their structures solved at high-resolution. From these structures, models of the filament and the hook were built, enabling the understanding of their functional mechanism.