The streptococcal hemoprotein receptor: a moonlighting protein or a virulence factor?

The β-hemolytic group A streptococcus (GAS) is a major pathogen that readily uses hemoglobin to satisfy its requirements for iron. The streptococcal hemoprotein receptor in GAS plays a central role in heme utilization and binds fibronectin and laminin in vitro. Shr inactivation attenuates the virulent M1T1 GAS strain in two murine infection models and reduces bacterial growth in blood and binding to laminin. Shr impact on the globally disseminated M1T1 strain underscores the importance of heme uptake in GAS pathogenesis and raises the possibility of targeting heme-uptake proteins in the development of new methods to combat GAS infections.