BEHAVIORAL RESPONSES TO CHEMICAL CUES BY BACTERIA

Abstract--Bacterial chemotaxis presents a model sensory system in which cells modulate the direction of rotation of their flagella in response to gra-dients of certain chemicals. The chemotactic machinery of Escherichia coli is currently being systematically reduced to its individual components hrough the accomplishments of behavioral, physical, genetic, molecular genetic, and biochemical analyses. Thirteen of the so called "MCP-related " class of che-motaxis gene products are known. Transmembrane methyl-accepting che-motaxis proteins (MCPs) are important for the chemical sensing, signal gen-eration, and sensory adaptation processes. Soluble chemotaxis proteins relay information from these MCPs to structural components of the flagella re-ferred to as switch proteins. Emphasis here is on the separate roles each of these groups of chemotaxis proteins perform, as well as their protein-protein relationships. Key Words--Bacteria, chemotaxis, methyl-accepting chemotaxis proteins, molecular biology, signal transduction, switch proteins