The coordinated secretion of proteins by bacteria consists of an essential biological process with tremendous impact on human health. Biotechnology is studying these systems in order to optimise their performance as small 'factories' for the production of biopharmaceuticals, whereas biomedicine is interested in their role in human pathogenicity.
The general secretory (Sec) pathway is responsible for the secretion and/or translocation of the vast majority of bacterial proteins in most bacteria. Recently, a second mainstream export system was discovered called the twin-arginine translocation (Tat) pathway. This system differs significantly from the Sec pathway in terms of structure, mechanism and specificity. This is a widely conserved and essential bacterial protein secretion pathway that has also been involved in the secretion of virulence factors by human pathogens.
