PDBsum entry 1fnl

Immune system receptor

PDB id: 1fnl

Contents

Protein chain

173 a.a. *

Metals

_HG ×2

Waters ×225

* Residue conservation analysis

PDB id:

1fnl

Name:

Immune system receptor

Title:

Crystal structure of the extracellular domain of a human fcgriii

Structure:

Low affinity immunoglobulin gamma fc region receptor iii-b. Chain: a. Fragment: extracellular ligand binding domain. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

1.80Å R-factor: 0.184 R-free: 0.216

Authors:

Y.Zhang,C.C.Boesen,S.Radaev,A.G.Brooks,W.H.Fridman,C.Sautes-Fridman, P.D.Sun

Key ref:

Y.Zhang et al. (2000). Crystal structure of the extracellular domain of a human Fc gamma RIII. Immunity, 13, 387-395. PubMed id: 11021536 DOI: 10.1016/S1074-7613(00)00038-8

Date:

22-Aug-00 Release date: 22-Nov-00

Protein chain

O75015  (FCG3B_HUMAN) -  Low affinity immunoglobulin gamma Fc region receptor III-B from Homo sapiens

Seq: 233 a.a.

Struc: 173 a.a.*

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

DOI no: 10.1016/S1074-7613(00)00038-8

Immunity 13:387-395 (2000)

PubMed id: 11021536

Crystal structure of the extracellular domain of a human Fc gamma RIII.

Y.Zhang, C.C.Boesen, S.Radaev, A.G.Brooks, W.H.Fridman, C.Sautes-Fridman, P.D.Sun.

ABSTRACT

Fc receptors play a major role in immune defenses against pathogens and in inflammatory processes. The crystal structure of a human immunoglobulin receptor, FcgammaRIIIb, has been determined to 1.8 A resolution. The overall fold consists of two immunoglobulin-like domains with an acute interdomain hinge angle of approximately 50 degrees. Trp-113, wedged between the N-terminal D1 and the C-terminal D2 domains, appears to further restrict the hinge angle. The putative Fc binding region of the receptor carries a net positive charge complementary to the negative-charged receptor binding regions on Fc. A 1:1 binding stoichiometry between the receptor and Fc was measured by both the equilibrium and nonequilibrium size-exclusion chromatography. Two separate parallel dimers are observed in the crystal lattice, offering intriguing models for receptor aggregation.

Selected figure(s)

Figure 3.
Figure 3. The Structure of Fc Binding Region(A) The putative Fc binding region. The D1 and D2 domains of FcγRIII are shown in dark blue and green, respectively. Residues in the putative ligand binding region of FcγRIII are shown in ball-and-stick model. The D2 domain of Fc epsilon RI superimposed onto the D2 domain of FcγRIII is shown in light blue.(B) The Grasp representation of the electrostatic potential distribution at the putative interface of FcγRIII and the C[H]2 domain of IgG. Positive potentials are colored in blue, and negative potentials are in red. The putative interface regions are highlighted. The coordinates for Fc are taken from the structure of IgG2a, Protein Data Bank entry 1IGT.

Figure 5.
Figure 5. Fc Receptor Dimerization and Aggregation Model(A) Crystal lattice packing of molecule A (in red) and B (in green).(B) AA, BB, and AB parallel dimers. The dimers are formed through translational symmetry. The view is 90° from that of panel (A). D1 and D2 domains are colored in light blue and green. The interface residues are shown as ball-and-sticks in dark blue and green for the D1 and D2 domains, respectively. The predicted glycosylation sites are shown in magenta. The putative Fc binding loops are colored red. AB parallel dimer is formed between the two molecules in each asymmetric unit.(C) A hypothetical model of receptor aggregation based on the observed parallel AB dimer (in green) in crystal lattice. The antibody coordinates, colored in magenta and blue, are from Protein Data Bank entry 1IGT.

The above figures are reprinted by permission from Cell Press: Immunity (2000, 13, 387-395) copyright 2000.

Figures were selected by an automated process.