Part of an ABC transporter complex involved in the uptake of maltodextrins. Binds glycogen-derived linear maltooligosaccharides increasing in size from maltotriose to maltooctaose with the highest affinity for maltotriose. Has a very weak affinity for maltose. Has also a very low affinity for maltotetraitol, indicating that the binding is selective for maltooligosaccharides with an intact reducing end. By maltose. Belongs to the bacterial solute-binding protein 1 family.