3AIH

Human OS-9 MRH domain complexed with alpha3,alpha6-Man5

Summary for 3AIH

• Entry DOI: 10.2210/pdb3aih/pdb
• Related: 1GP0 1KEO 1M6P 1Q25 1SZ0 2RL7 2RL8 2RL9 2V5N 2V5O 2V5P
• Descriptor: Protein OS-9, alpha-D-mannopyranose-(1-6)-alpha-D-mannopyranose-(1-6)-beta-D-mannopyranose (3 entities in total)
• Functional Keywords: beta barrel, lectin, sugar binding protein
• Biological source: Homo sapiens (human)
• Cellular location: Endoplasmic reticulum lumen : Q13438
• Total number of polymer chains: 2
• Total formula weight: 29849.02

Authors

Satoh, T.,Chen, Y.,Hu, D.,Hanashima, S.,Yamamoto, K.,Yamaguchi, Y. (deposition date: 2010-05-14, release date: 2010-12-22, Last modification date: 2024-10-23)

Primary citation

Satoh, T.,Chen, Y.,Hu, D.,Hanashima, S.,Yamamoto, K.,Yamaguchi, Y.
Structural Basis for Oligosaccharide Recognition of Misfolded Glycoproteins by OS-9 in ER-Associated Degradation
Mol.Cell, 40:905-916, 2010

PubMed Abstract: Misfolded glycoproteins are translocated from endoplasmic reticulum (ER) into the cytosol for proteasome-mediated degradation. A mannose-6-phosphate receptor homology (MRH) domain is commonly identified in a variety of proteins and, in the case of OS-9 and XTP3-B, is involved in glycoprotein ER-associated degradation (ERAD). Trimming of outermost α1,2-linked mannose on C-arm of high-mannose-type glycan and binding of processed α1,6-linked mannosyl residues by the MRH domain are critical steps in guiding misfolded glycoproteins to enter ERAD. Here we report the crystal structure of a human OS-9 MRH domain (OS-9(MRH)) complexed with α3,α6-mannopentaose. The OS-9(MRH) has a flattened β-barrel structure with a characteristic P-type lectin fold and possesses distinctive double tryptophan residues in the oligosaccharide-binding site. Our crystallographic result in conjunction with nuclear magnetic resonance (NMR) spectroscopic and biochemical results provides structural insights into the mechanism whereby OS-9 specifically recognizes Manα1,6Manα1,6Man residues on the processed C-arm through the continuous double tryptophan (WW) motif.

PubMed: 21172656
DOI: 10.1016/j.molcel.2010.11.017

Experimental method

X-RAY DIFFRACTION (2.1 Å)