The objective of this project is to discover the mechanisms that bacteria use for getting attracted or repelled by chemicals (chemotaxis): 1) How are the chemicals sensed? We now know that there are chemoreceptors for this function. 2) How do bacterial flagella work? We now know that they function by rotaating, like a propellor, and they can rotate both clockwise and counterclockwise. 3) How is the sensed information transmitted to the flagella to tell them in which direction to rotate, in order to bring the bacterium toward the attractants or away from the repellents? We discovered the methylation of a set of membrane proteins, the so-called methyl-accepting chemotaxis proteins (MCPs), that serve to communicate between the chemoreceptors and the flagella. These proteins will be further studied during the coming year.