5LFR
Crystal structure of glycosylated Myelin-associated glycoprotein (MAG) Ig1-3
Summary for 5LFR
| Entry DOI | 10.2210/pdb5lfr/pdb |
| Descriptor | Myelin-associated glycoprotein, alpha-D-mannopyranose-(1-3)-alpha-D-mannopyranose-(1-6)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, alpha-D-mannopyranose-(1-3)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (8 entities in total) |
| Functional Keywords | myelin, cell adhesion molecule, cell adhesion |
| Biological source | Mus musculus (House Mouse) |
| Cellular location | Cell membrane ; Single-pass type I membrane protein : P20917 |
| Total number of polymer chains | 2 |
| Total formula weight | 74099.27 |
| Authors | Pronker, M.F.,Janssen, B.J.C. (deposition date: 2016-07-04, release date: 2016-12-14, Last modification date: 2024-10-23) |
| Primary citation | Pronker, M.F.,Lemstra, S.,Snijder, J.,Heck, A.J.,Thies-Weesie, D.M.,Pasterkamp, R.J.,Janssen, B.J. Structural basis of myelin-associated glycoprotein adhesion and signalling. Nat Commun, 7:13584-13584, 2016 Cited by PubMed Abstract: Myelin-associated glycoprotein (MAG) is a myelin-expressed cell-adhesion and bi-directional signalling molecule. MAG maintains the myelin-axon spacing by interacting with specific neuronal glycolipids (gangliosides), inhibits axon regeneration and controls myelin formation. The mechanisms underlying MAG adhesion and signalling are unresolved. We present crystal structures of the MAG full ectodomain, which reveal an extended conformation of five Ig domains and a homodimeric arrangement involving membrane-proximal domains Ig4 and Ig5. MAG-oligosaccharide complex structures and biophysical assays show how MAG engages axonal gangliosides at domain Ig1. Two post-translational modifications were identified-N-linked glycosylation at the dimerization interface and tryptophan C-mannosylation proximal to the ganglioside binding site-that appear to have regulatory functions. Structure-guided mutations and neurite outgrowth assays demonstrate MAG dimerization and carbohydrate recognition are essential for its regeneration-inhibiting properties. The combination of trans ganglioside binding and cis homodimerization explains how MAG maintains the myelin-axon spacing and provides a mechanism for MAG-mediated bi-directional signalling. PubMed: 27922006DOI: 10.1038/ncomms13584 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.12 Å) |
Structure validation
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