Probably part of an ABC transporter complex involved in carbohydrate transport. Exists as a monomer, homodimer, homotrimer and homotetramer; oligomerization increases with higher protein concentration. This protein has potential use in the development of vaccines and antimicrobials against pneumococcus, because of its extracellular localization and the essentiality of carbohydrate import for the pneumococcal metabolism. The characterization protocol developed for this protein can be helpful in structure-based design of inhibitors for the carbohydrate-binding proteins in general. Belongs to the bacterial solute-binding protein 1 family.