Part of the ABC transporter complex GgtABCD involved in the uptake of the osmoprotective compounds glucosylglycerol (GG), sucrose and trehalose. Binds glucosylglycerol and exhibits a somewhat lower affinity towards sucrose and a substantially lower affinity towards trehalose. The complex is composed of two ATP-binding proteins (GgtA), two transmembrane proteins (GgtC and GgtD) and a solute-binding protein (GgtB). Expression is very low in cells grown in basal medium but increases significantly after a salt shock. Inactivation of the gene results in loss of the ability to take up glucosylglycerol and sucrose, as well as to accumulate exogenous trehalose. Insertion causes leakage of glucosylglycerol from the cells into the medium. Belongs to the bacterial solute-binding protein 1 family.