2D6M

Crystal structure of mouse galectin-9 N-terminal CRD in complex with lactose

Summary for 2D6M

• Entry DOI: 10.2210/pdb2d6m/pdb
• Related: 2D6K 2D6L 2D6N 2D6O 2D6P
• Related PRD ID: PRD_900008
• Descriptor: lectin, galactose binding, soluble 9, beta-D-galactopyranose-(1-4)-alpha-D-glucopyranose (3 entities in total)
• Functional Keywords: beta sandwich, carbohydrate binding protein, galectin, sugar binding protein, structural genomics
• Biological source: Mus musculus (house mouse)
• Total number of polymer chains: 2
• Total formula weight: 37024.13

Authors

Nagae, M.,Nishi, N.,Nakamura, T.,Wakatsuki, S.,Kato, R. (deposition date: 2005-11-14, release date: 2006-09-26, Last modification date: 2023-10-25)

Primary citation

Nagae, M.,Nishi, N.,Murata, T.,Usui, T.,Nakamura, T.,Wakatsuki, S.,Kato, R.
Crystal Structure of the Galectin-9 N-terminal Carbohydrate Recognition Domain from Mus musculus Reveals the Basic Mechanism of Carbohydrate Recognition
J.Biol.Chem., 281:35884-35893, 2006

PubMed Abstract: The galectins are a family of beta-galactoside-binding animal lectins with a conserved carbohydrate recognition domain (CRD). They have a high affinity for small beta-galactosides, but binding specificity for complex glycoconjugates varies considerably within the family. The ligand recognition is essential for their proper function, and the structures of several galectins have suggested their mechanism of carbohydrate binding. Galectin-9 has two tandem CRDs with a short linker, and we report the crystal structures of mouse galectin-9 N-terminal CRD (NCRD) in the absence and the presence of four ligand complexes. All structures form the same dimer, which is quite different from the canonical 2-fold symmetric dimer seen for galectin-1 and -2. The beta-galactoside recognition mechanism in the galectin-9 NCRD is highly conserved among other galectins. In the apo form structure, water molecules mimic the ligand hydrogen-bond network. The galectin-9 NCRD can bind both N-acetyllactosamine (Galbeta1-4GlcNAc) and T-antigen (Galbeta1-3GalNAc) with the proper location of Arg-64. Moreover, the structure of the N-acetyllactosamine dimer (Galbeta1-4GlcNAcbeta1-3Galbeta1-4GlcNAc) complex shows a unique binding mode of galectin-9. Finally, surface plasmon resonance assay showed that the galectin-9 NCRD forms a homophilic dimer not only in the crystal but also in solution.

PubMed: 16990264
DOI: 10.1074/jbc.M606648200

Experimental method

X-RAY DIFFRACTION (1.6 Å)