The N-terminal domain of the R28 protein promotes group A adhesion to host cells via direct binding to three integrins.

Group A (GAS) is a human-specific pathogen responsible for a wide range of diseases, ranging from superficial to life-threatening invasive infections, including endometritis, and autoimmune sequelae. GAS strains express a vast repertoire of virulence factors that varies depending on the strain genotype, and many adhesin proteins that enable GAS to adhere to host cells are restricted to some genotypes. GAS is the third most prevalent genotype in invasive infections in France and is associated with gyneco-obstetrical infections.