Mathematical Biology seminar Kelly Hughes Department of Biology University of Utah "Mechanism of rod-hook length control in flagellar biosynthesis" December 7, 2005 3:05pm, LCB 215 The bacterial flagellum is the poster child of intelligent design theorists. Basically, it is so complicated and perfect it couldn't possibly have evolved. The length of the flagellar rod (the drive shaft of the flagellar motor) is intrinsic to the rod itself. The last rod structural component has signals to control its length to be 22 nm. I will show you what happens when we mutate that control. The hook is a flexible coupling (U-joint) between the rod and the external rigid flagellar filament (propeller) and it is controlled to be 55 nm +/- 5 nm in length. I will show you how a protein, FliK, acts as a molecular ruler to determine this precise length control for the hook. I will also describe another protein, Fluke, that hides the design flaws to fool the intelligent design theorists in this marvelous molecular bio-nano-machine.