INTERACTING COMPONENTS OF THE FLAGELLAR MOTOR OF ESCHERICHIA-COLI REVEALED BY THE 2-HYBRID SYSTEM IN YEAST

The ability of the flagellar motor of Escherichia coli to switch betwe en clockwise and counterclockwise modes of operation is ultimately res ponsible for the swimming behavior of the cell. Three motor proteins, FIG, FliM, and FliN, have been implicated in this process. Using the t wo-hybrid system in Saccharomyces cerevisiae, we demonstrated strong i nteractions between FliG/FliM, FliM/FliM, and FliM/FliN. A screen for other components that might interact with FIG revealed interactions wi th FliF (the MS ring protein) and H-NS (a histone-like protein). Regio ns of proteins important for several of these interactions were identi fied by mutational analysis. The implications for motor assembly and f unction are discussed. (C) 1996 Academic Press Limited