Part of the ABC transporter complex DasABC-MsiK involved in N,N'-diacetylchitobiose ((GlcNAc)2) uptake. Binds specifically to (GlcNAc)2. Can also bind to GlcNAc, (GlcNAc)3, (GlcNAc)4 and (GlcNAc)5, but it exhibits the highest affinity for (GlcNAc)2 (PubMed:17351098). Involved in the control of morphological differentiation (PubMed:18227241). The complex is composed of two ATP-binding proteins (MsiK), two transmembrane proteins (DasB and DasC) and a solute-binding protein (DasA). Strongly induced by (GlcNAc)2, (GlcNAc)3 and colloidal chitin (PubMed:17351098, PubMed:18227241). Repressed by DasR (PubMed:18227241). Disruption of the gene decreases (GlcNAc)2 uptake. Mutant shows higher chitinase activity (PubMed:17351098). Null mutant shows medium-dependent development, only failing to produce aerial hyphae and spores on glucose-containig media. Under conditions that allow sporulation, highly aberrant spores with many prematurely produced germ tubes are observed (PubMed:18227241). Belongs to the bacterial solute-binding protein 1 family.