PDBsum entry 6grq

Immune system

PDB id: 6grq

Contents

Protein chain

536 a.a.

Ligands

NAG-NAG

NAG

PDB id:

6grq

Name:

Immune system

Title:

Paired immunoglobulin-like receptor b (pirb) or leukocyte immunoglobulin-like receptor subfamily b member 3 (lilrb3) full extracellular domain

Structure:

Paired immunoglobulin-like receptor b. Chain: a. Engineered: yes

Source:

Mus musculus. House mouse. Organism_taxid: 10090. Gene: pirb, lilrb3. Expressed in: homo sapiens. Expression_system_taxid: 9606

Resolution:

3.30Å R-factor: 0.250 R-free: 0.295

Authors:

H.C.Vlieg,E.G.Huizinga,B.J.C.Janssen

Key ref:

H.C.Vlieg et al. (2019). Structure and flexibility of the extracellular region of the PirB receptor. J Biol Chem, 294, 4634-4643. PubMed id: 30674550 DOI: 10.1074/jbc.RA118.004396

Date:

12-Jun-18 Release date: 06-Feb-19

Protein chain

Q8K4V6  (Q8K4V6_MOUSE) -  Paired immunoglobulin-like receptor B (Fragment) from Mus musculus

Seq: 697 a.a.

Struc: 536 a.a.

DOI no: 10.1074/jbc.RA118.004396

J Biol Chem 294:4634-4643 (2019)

PubMed id: 30674550

Structure and flexibility of the extracellular region of the PirB receptor.

H.C.Vlieg, E.G.Huizinga, B.J.C.Janssen.

ABSTRACT

Murine paired immunoglobulin receptor B (PirB) and its human ortholog leukocyte immunoglobulin-like receptor B2 (LILRB2) are widely expressed inhibitory receptors that interact with a diverse set of extracellular ligands and exert functions ranging from down-regulation of immune responses to inhibition of neuronal growth. However, structural information that could shed light on how PirB interacts with its ligands is lacking. Here, we report crystal structures of the PirB ectodomain; the first full ectodomain structure for a LILR family member, at 3.3-4.5 Å resolution. The structures reveal that PirB's six Ig-like domains are arranged at acute angles, similar to the structures of leukocyte immunoglobulin-like receptor (LILR) and killer-cell immunoglobulin-like receptor (KIR). We observe that this regular arrangement is followed throughout the ectodomain, resulting in an extended zigzag conformation. In two out of the five structures reported here, the repeating zigzag is broken by the first domain that can adopt two alternative orientations. Quantitative binding experiments revealed a 9 μm dissociation constant for PirB-myelin-associated glycoprotein (MAG) ectodomain interactions. Taken together, these structural findings and the observed PirB-MAG interactions are compatible with a model for intercellular signaling in which the PirB extracellular domains, which point away from the cell surface, enable interaction with ligands in trans.