Laminin G-like domains: dystroglycan-specific lectins. (June 2019)

• Record Type: Journal Article
• Authors: Hohenester, Erhard
• Is Part Of: Current opinion in structural biology. Volume 56(2019)
• Page Start: 56
• Page End: 63
• Publication Date: 2019-06
• Subjects: Molecular biology -- Periodicals; 570
• DOI: 10.1016/j.sbi.2018.11.007
• Languages: English
• ISSNs: 0959-440X

Abstract

Highlights: The chemical structure of dystroglycan's laminin-binding modification is now known. Laminin G-like domains bind to a polysaccharide of glucuronic acid-xylose units. Crystal structure analysis has revealed the atomic details of this interaction. Abstract : A unique O -mannose-linked glycan on the transmembrane protein dystroglycan binds a number of extracellular matrix proteins containing laminin G-like (LG) domains. The dystroglycan-matrix interaction is essential for muscle function: disrupted biosynthesis of the matrix-binding modification causes several forms of muscular dystrophy. The complete chemical structure of this modification has been deciphered in the past few years. We now know that LG domains bind to a glycosaminoglycan-like polysaccharide of [-3GlcAβ1, 3Xylα1-] units, termed matriglycan, that is attached to a highly unusual heptasaccharide linker. X-ray crystallography has revealed the principles of Ca 2+ -dependent matriglycan binding by LG domains. In this review, the new structural insights are applied to the growing number of LG domain-containing proteins that bind dystroglycan. It is proposed that LG domains be recognised as 'D-type' lectins to indicate their conserved function in dystroglycan binding.