Recognition of Bisecting N-Acetylglucosamine: STRUCTURAL BASIS FOR ASYMMETRIC INTERACTION WITH THE MOUSE LECTIN DENDRITIC CELL INHIBITORY RECEPTOR 2
Nagae, M., Yamanaka, K., Hanashima, S., Ikeda, A., Morita-Matsumoto, K., Satoh, T., Matsumoto, N., Yamamoto, K., Yamaguchi, Y.(2013) J Biol Chem 288: 33598-33610
- PubMed: 24108122 
- DOI: https://doi.org/10.1074/jbc.M113.513572
- Primary Citation of Related Structures:  
3VYJ, 3VYK - PubMed Abstract: 
Dendritic cell inhibitory receptor 2 (DCIR2) is a C-type lectin expressed on classical dendritic cells. We recently identified the unique ligand specificity of mouse DCIR2 (mDCIR2) toward biantennary complex-type glycans containing bisecting N-acetylglucosamine (GlcNAc). Here, we report the crystal structures of the mDCIR2 carbohydrate recognition domain in unliganded form as well as in complex with an agalactosylated complex-type N-glycan unit carrying a bisecting GlcNAc residue. Bisecting GlcNAc and the α1-3 branch of the biantennary oligosaccharide asymmetrically interact with canonical and non-canonical mDCIR2 residues. Ligand-protein interactions occur directly through mDCIR2-characteristic amino acid residues as well as via a calcium ion and water molecule. Our structural and biochemical data elucidate for the first time the unique binding mode of mDCIR2 for bisecting GlcNAc-containing glycans, a mode that contrasts sharply with that of other immune C-type lectin receptors such as DC-SIGN.
Organizational Affiliation: 
Structural Glycobiology Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center, RIKEN Global Research Cluster, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.