5XTW

Crystal structure of the CysR-CTLD2 fragment of human MR at acidic pH

Summary for 5XTW

• Entry DOI: 10.2210/pdb5xtw/pdb
• Descriptor: Macrophage mannose receptor 1, 2-(N-MORPHOLINO)-ETHANESULFONIC ACID, CALCIUM ION (3 entities in total)
• Functional Keywords: collagen binding, lectin-activity, endocytic receptor, immune receptor, sugar binding protein
• Biological source: Homo sapiens (Human)
• Cellular location: Endosome membrane ; Single-pass type I membrane protein : P22897
• Total number of polymer chains: 8
• Total formula weight: 437105.68

Authors

He, Y.,Hu, Z. (deposition date: 2017-06-21, release date: 2017-12-27, Last modification date: 2023-11-22)

Primary citation

Hu, Z.,Shi, X.,Yu, B.,Li, N.,Huang, Y.,He, Y.
Structural Insights into the pH-Dependent Conformational Change and Collagen Recognition of the Human Mannose Receptor
Structure, 26:60-71.e3, 2018

PubMed Abstract: Mannose receptor (MR, CD206) is an endocytic receptor on microphages and dendritic cells. It recognizes multiple ligands and plays important roles in regulating immune responses and maintaining glycoprotein homeostasis. However, the structure and functional mechanism of MR remain unclear. Here we determine the crystal structures of the N-terminal fragments of MR and reveal the potential binding mode of collagen on the fibronectin II domain. The SAXS and other biophysical data suggest that MR adopts an extended conformation at physiological pH and undergoes conformational changes as pH decreases, resulting in a compact conformation in an acidic environment. Moreover, biochemical data show that MR binds to collagen in a Ca-enhanced manner at physiological pH, whereas Ca has no effect on the binding at acidic pH. These results provide a model for the dynamic mechanism of MR regarding its ligand binding and release during the recycling between cell surface and endosomes.

PubMed: 29225077
DOI: 10.1016/j.str.2017.11.006

Experimental method

X-RAY DIFFRACTION (3.2 Å)