PDBsum entry 4c9f

Membrane protein

PDB id: 4c9f

Contents

Protein chains

132 a.a.

Ligands

GQ1-GLC ×2

GQ1-GLC-GLC-GLC

SO4 ×10

GQ1 ×3

Metals

_CA ×4

Waters ×164

PDB id:

4c9f

Name:

Membrane protein

Title:

Structure of sign-r1 in complex with sulfodextran

Structure:

Cd209 antigen-like protein b. Chain: a, b, c, d. Fragment: crd, residues 191-323. Synonym: dc-sign-related protein 1, dc-signr1, otb7, sign-r1

Source:

Mus musculus. House mouse. Organism_taxid: 10090. Cell: macrophages

Resolution:

2.60Å R-factor: 0.193 R-free: 0.233

Authors:

N.Silva-Martin,S.G.Bartual,A.Rodriguez,E.Ramirez,P.Chacon, R.M.Anthony,C.G.Park,J.A.Hermoso

Key ref:

N.Silva-Martín et al. (2014). Structural basis for selective recognition of endogenous and microbial polysaccharides by macrophage receptor SIGN-R1. Structure, 22, 1595-1606. PubMed id: 25450767 DOI: 10.1016/j.str.2014.09.001

Date:

02-Oct-13 Release date: 15-Oct-14

Protein chains

Q8CJ91  (C209B_MOUSE) -  CD209 antigen-like protein B from Mus musculus

Seq: 325 a.a.

Struc: 132 a.a.

DOI no: 10.1016/j.str.2014.09.001

Structure 22:1595-1606 (2014)

PubMed id: 25450767

Structural basis for selective recognition of endogenous and microbial polysaccharides by macrophage receptor SIGN-R1.

N.Silva-Martín, S.G.Bartual, E.Ramírez-Aportela, P.Chacón, C.G.Park, J.A.Hermoso.

ABSTRACT

SIGN-R1 is a principal receptor for microbial polysaccharides uptake and is responsible for C3 fixation via an unusual complement activation pathway on splenic marginal zone macrophages. In these macrophages, SIGN-R1 is also involved in anti-inflammatory activity of intravenous immunoglobulin by direct interaction with sialylated Fcs. The high-resolution crystal structures of SIGN-R1 carbohydrate recognition domain and its complexes with dextran sulfate or sialic acid, and of the sialylated Fc antibody provide insights into SIGN-R1’s selective recognition of a-2,6-sialylated glycoproteins. Unexpectedly, an additional binding site has been found in the SIGNR1 carbohydrate recognition domain, structurally separate from the calcium-dependent carbohydrate-binding site. This secondary binding site could bind repetitive molecular patterns, as observed in microbial polysaccharides, in a calcium-independent manner. These two binding sites may allow SIGNR1 to simultaneously bind both immune glycoproteins and microbial polysaccharide components, accommodating SIGN-R1’s ability to relate the recognition of microbes to the activation of the classical complement pathway.