Part of the ABC transporter complex NgcEFG-MsiK involved in N,N'-diacetylchitobiose ((GlcNAc)2) uptake. Binds (GlcNAc)2. Can also bind GlcNAc. The complex is composed of two ATP-binding proteins (MsiK), two transmembrane proteins (NgcF and NgcG) and a solute-binding protein (NgcE). Constitutively expressed. Slightly induced by GlcNAc, (GlcNAc)2 and chitin. Repressed by DasR. Predicted to be exported by the Tat system. The position of the signal peptide cleavage has not been experimentally proven. Disruption of the gene delays (GlcNAc)2 consumption, but does not affect GlcNAc consumption ability. Deletion reduces the level of chitinase activity induced in the presence of (GlcNAc)2. Belongs to the bacterial solute-binding protein 1 family.