This work focuses on the protein/protein and DNA protein interactions that are required for regulation of colanic acid polysaccharide capsule expression in Escherichia coli. These interactions are incorporated into a model that will be tested. The first two sections of this work examine the protein/protein interactions of three of the capsule synthesis regulators: Rcs, RcsB, and RcsC. These interactions will be examined by genetic and biochemical analyses. The third section is designed to elucidate the protein/DNA interactions that are required at the promoter of the capsule genes. Molecular genetic methods will be used for these studies. %%% Polysaccharide capsules are often expressed only under certain adverse conditions which allows the bacteria producing them to survive better in a natural environment. Because the synthesis levels of capsules vary with the environment, it is important to understand how their regulatory networks control capsule production. The regulatory network for colanic acid is a model for the control of synthesis of several other capsule regulatory networks will lead to a greater understanding of how the environment affects the production of these survival factors.
