PDBsum entry 4f7c

Immune system

PDB id: 4f7c

Contents

Protein chains

269 a.a.

97 a.a.

Ligands

NAG-NAG

NAG-NAG-BMA ×2

NAG-NAG-BMA-BMA

0SG ×2

Waters ×29

PDB id:

4f7c

Name:

Immune system

Title:

Crystal structure of bovine cd1d with bound c12-di-sulfatide

Structure:

Cd1d antigen, d polypeptide. Chain: a, c. Fragment: unp residues 129-405. Synonym: t cell surface glycoprotein cd1d antigen. Engineered: yes. Beta-2-microglobulin. Chain: b, d. Fragment: unp residues 21-118. Synonym: lactollin.

Source:

Bos taurus. Bovine. Organism_taxid: 9913. Gene: cd1d. Expressed in: spodoptera frugiperda. Expression_system_taxid: 7108. Gene: b2m.

Resolution:

2.86Å R-factor: 0.225 R-free: 0.291

Authors:

J.Wang,D.M.Zajonc

Key ref:

J.Wang et al. (2012). Crystal structures of bovine CD1d reveal altered αGalCer presentation and a restricted A' pocket unable to bind long-chain glycolipids. Plos One, 7, e47989. PubMed id: 23110152

Date:

15-May-12 Release date: 14-Nov-12

Protein chains

A1L565  (A1L565_BOVIN) -  CD1D antigen, d polypeptide (Fragment) from Bos taurus

Seq: 445 a.a.

Struc: 269 a.a.*

Protein chains

P01888  (B2MG_BOVIN) -  Beta-2-microglobulin from Bos taurus

Seq: 118 a.a.

Struc: 97 a.a.

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Plos One 7:e47989 (2012)

PubMed id: 23110152

Crystal structures of bovine CD1d reveal altered αGalCer presentation and a restricted A' pocket unable to bind long-chain glycolipids.

J.Wang, J.Guillaume, N.Pauwels, S.Van Calenbergh, I.Van Rhijn, D.M.Zajonc.

ABSTRACT

NKT cells play important roles in immune surveillance. They rapidly respond to pathogens by detecting microbial glycolipids when presented by the non-classical MHC I homolog CD1d. Previously, ruminants were considered to lack NKT cells due to the lack of a functional CD1D gene. However, recent data suggest that cattle express CD1d with unknown function. In an attempt to characterize the function of bovine CD1d, we assessed the lipid binding properties of recombinant Bos taurus CD1d (boCD1d) in vitro. BoCD1d is able to bind glycosphingolipids (GSLs) with fatty acid chain lengths of C(18), while GSLs with fatty acids of C(24) do not bind. Crystal structures of boCD1d bound to a short-chain C(12)-di-sulfatide antigen, as well as short-chain C(16)-αGalCer revealed that the Á pocket of boCD1d is restricted in size compared to that of both mouse and human CD1d, explaining the inability of long chain GSL's to bind to boCD1d. Moreover, while di-sulfatide is presented similarly compared to the presentation of sulfatide by mouse CD1d, αGalCer is presented differently at the cell surface, due to an amino acid Asp151Asn substitution that results in loss of intimate contacts between the αGalCer headgroup and CD1d. The altered αGalCer presentation by boCD1d also explains its lack of cross-activation of mouse iNKT cells and raises the interesting question of the nature and function of bovine lipid-reactive T cells.