Part of the ABC transporter complex MalEFGK involved in trehalose/maltose import. Binds maltose and trehalose. The complex is composed of two ATP-binding proteins (MalK), two transmembrane proteins (MalG and MalF) and a solute-binding protein (MalE). Glycosylated. The protein assumes different conformations with different physical properties depending whether maltose or trehalose is bound to the protein. Belongs to the bacterial solute-binding protein 1 family.