HETEROLOGOUS PROTEIN SECRETION AND THE VERSATILE ESCHERICHIA-COLI HEMOLYSIN TRANSLOCATOR

Heterologous proteins synthesized in the Gram-negative bacterium Esche richia coli in bioreactor culture may accumulate in one of three 'comp artments': the cytoplasm, the periplasm, or the extracellular medium. Many overexpressed proteins from various origins have been purified fr om each of these locations. However, to date, each system has required specific tailoring to meet the stringent requirements for each protei n product to ensure correct folding, activity and appropriate yield. T he E. coli haemolysin secretion system appears to provide a flexible m echanism with which to secrete a wide variety of heterologous fusion p roteins into the extracellular medium.