PDBsum entry 1h9v

Immune system, membrane protein

PDB id: 1h9v

Contents

Protein chain

172 a.a. *

* Residue conservation analysis

PDB id:

1h9v

Name:

Immune system, membrane protein

Title:

Human fc-gamma-receptor iia (fcgriia), monoclinic

Structure:

Low affinity immunoglobulin gamma fc receptor ii-a. Chain: a. Fragment: immunoglobulin g binding domain residue 5-177. Synonym: fc-gamma rii-a, fcrii-a, igg fc receptor ii-a, fc-gamma- riia, cd32, cdw32. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Variant: high responder. Cellular_location: extracellular. Expressed in: escherichia coli. Expression_system_taxid: 469008. Other_details: refolded from inclusion bodies

Biol. unit:

Monomer (from PDB file)

Resolution:

3.00Å R-factor: not given

Authors:

P.Sondermann,J.Kaiser,U.Jacob

Key ref:

P.Sondermann et al. (2001). Molecular basis for immune complex recognition: a comparison of Fc-receptor structures. J Mol Biol, 309, 737-749. PubMed id: 11397093 DOI: 10.1006/jmbi.2001.4670

Date:

21-Mar-01 Release date: 21-Jun-01

Protein chain

P12318  (FCG2A_HUMAN) -  Low affinity immunoglobulin gamma Fc region receptor II-a from Homo sapiens

Seq: 317 a.a.

Struc: 172 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

DOI no: 10.1006/jmbi.2001.4670

J Mol Biol 309:737-749 (2001)

PubMed id: 11397093

Molecular basis for immune complex recognition: a comparison of Fc-receptor structures.

P.Sondermann, J.Kaiser, U.Jacob.

ABSTRACT

Once antigen is opsonised by IgG it is removed from the circulation by Fcgamma-receptor expressing cells. Fcgamma-receptors are type I transmembrane molecules that carry extracellular parts consisting of two or three immunoglobulin domains. Previously solved structures of Fc-receptors reveal that the N-terminal two Ig-like domains are arranged in a steep angle forming a heart-shaped structure. The crystal structure of the FcgammaRIII/hIgG1-Fc-fragment demonstrated that the Fc-fragment is recognised through loops of the C-terminal receptor domain of the FcgammaRIII. As the overall structure of the FcRs and their Ig ligands are very similar we modelled the Ig complexes with FcgammaRI, FcgammaRII and FcepsilonRIalpha based on the FcgammaRIII/hIgG1-Fc-fragment structure. The obtained models are consistent with the observed biochemical data and may explain the observed specificity and affinities.

Selected figure(s)

Figure 2.
Figure 2. Stereo ribbon representation of the sFcgRIII structure with residues relevant for IgG binding. The amino acid residues of FcgRIII which contact IgG are shown in ball-and-stick representation. Residues contacting the Cg2-A domain are coloured magenta and those contacting the Cg2-B domain green. Potential glycosylation sites are depicted as cyan balls and the disulphide bridges in yellow. The termini are labelled and the b-strands are numbered consecu- tively for the N-terminal domain in black and for the C-terminal domain in blue. The orientation is the same as Figure 1 (upper left), except that it is rotated by approximately 180 ° around the axis perpendicular to the plane of the paper. The Figure was created using MOLSCRIPT 37 and RASTER3D. 38

Figure 5.
Figure 5. Surface analysis of the FcR structures. A surface analysis was performed using the program GRASP 39 with the crystal structures of FcgRIIa, FcgRIIb, FcgRIII and FceRIa as well as the modelled FcgRI. The colour coding spans from hydrophobic (green) to hydrophilic (red) with potential glycosylation sites indicated as blue balls. The viewpoint is indicated with respect to the front view, which shows an identical orientation as in Figure 2. The IgG binding site is surrounded by a black box in the FcgRIII molecule. The unique hydrophobic region on the N-terminal domain of FcgRIII is circled.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2001, 309, 737-749) copyright 2001.

Figures were selected by an automated process.