Interaction Between Putative Epulopiscium sp. Type B Chemotaxis Proteins

Abstract

The main objective of this project is to determine binding between Epulopiscium sp. Type B methyl accepting chemotaxis proteins (MCP) and homologs of E. coli Che adapter proteins. Epulo is a large (up to 250 μm length) bacterium which moves by the use of flagella and lives symbiotically in the brown surgeon fish. Many bacteria that travel by the use of flagella use what is known as chemotaxis, a controlled movement in response to a ligand concentration gradient. E.coli has cell surface receptors that project into the periplasm which interact with Che proteins inside the cytosol when exposed to a specific ligand. The Che proteins then interact with the flagellar motors and cause them to turn in a clockwise or counterclockwise fashion based on the favorability of the ligand. These protein‐protein interactions can be explored by using a yeast two‐hybrid system. PCR was performed on genomic DNA from Epulo and two candidate MCP regions were selected for two‐hybrid analysis. Several putative CheA and W homologs were also cloned to test possible protein‐protein interactions. These studies will further the “interactome” map of Epulo and help elucidate the symbiotic mechanism. This research was funded by the Harwick College Chemistry Department.