PMID: 10619025 , Related PDB id: 1QU0

Authors:

Hohenester E, Tisi D, Talts JF, Timpl R

Title:

The crystal structure of a laminin G-like module reveals the molecular basis of alpha-dystroglycan binding to laminins, perlecan, and agrin.

Journal:

Mol Cell. 1999 Nov;4(5):783-92.

Abstract:

Laminin G-like (LG) modules in the extracellular matrix glycoproteins laminin, perlecan, and agrin mediate the binding to heparin and the cell surface receptor alpha-dystroglycan (alpha-DG). These interactions are crucial to basement membrane assembly, as well as muscle and nerve cell function. The crystal structure of the laminin alpha 2 chain LG5 module reveals a 14-stranded beta sandwich. A calcium ion is bound to one edge of the sandwich by conserved acidic residues and is surrounded by residues implicated in heparin and alpha-DG binding. A calcium-coordinated sulfate ion is suggested to mimic the binding of anionic oligosaccharides. The structure demonstrates a conserved function of the LG module in calcium-dependent lectin-like alpha-DG binding.