This paper explores the essential function of the PrsA-mediated system of influencing the amount and rate of protein secretion from Gram positive bacteria. During secretion, bacterial proteins face an obstacle course of extremes of charge, pH, unfolding and re-folding into native conformations in order to be of service in the adaptation of the bacterial cell to its environment. Recent evidence suggests that PrsA enhances the yield and efficiency of this secretion process through its influences on protein shape and stability (as a chaperone) as well as its effects on the bacterial cell wall itself. PrsA up- or down-regulation also affects cellular levels of many other factors that exert effects on the ubiquitous Sec secretory pathway. This represents an additional avenue for manipulating Gram positive bacteria to secrete the type and amount of heterologous proteins required, whether it is large or small. The PrsA system offers an attractive target for many beneficial clinical as well as industrial applications. More work should be done to fine-tune our understanding of its mechanisms of action.
PsrA, Gram positive, protein secretion, protein folding, antibiotic resistance