EspC, an autotransporter protein secreted by enteropathogenic Escherichia coli (EPEC), displays protease activity on human hemoglobin.

Some enteropathogenic Escherichia coli (EPEC) strains, which are an important cause of diarrhea among infants, secrete a serine protease autotransporter protein called EspC. The pathogenic role of EspC upon EPEC infection is unknown. In this study, we demonstrated that purified EspC protein, obtained from supernatants of EPEC cultures, interacted with hemoglobin and degraded it. Moreover, we have shown that EspC is a hemin-binding protein. We hypothesized that hemoglobin proteolysis by EspC may contribute to the utilization of heme and hemoglobin iron for bacterial growth.