This domain is an adhesive domain that binds to sialoglycan [1]. A Thr-Arg motif conserved across homologous carbohydrate-binding adhesins that may orient the sialic acid moiety of carbohydrate ligands [1].
The region featured in this family is found repeated in a number of bacterial surface proteins, such as Rib (Swiss:P72362) and alpha (Swiss:Q02192). These are expressed by group B streptococci, and Rib is thought to confer protective immunity.