PDBsum entry 1uct

Immune system

PDB id: 1uct

Contents

Protein chain

191 a.a. *

Waters ×68

* Residue conservation analysis

PDB id:

1uct

Name:

Immune system

Title:

Crystal structure of the extracellular fragment of fc alpha receptor i (cd89)

Structure:

Immunoglobulin alpha fc receptor. Chain: a. Fragment: residues 0-217. Synonym: fc alpha receptor i (cd89). Engineered: yes

Source:

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

Biol. unit:

Dimer (from PQS)

Resolution:

2.10Å R-factor: 0.210 R-free: 0.239

Authors:

Y.Ding,G.Xu,M.Yang,W.Zhang,Z.Rao

Key ref:

Y.Ding et al. (2003). Crystal structure of the ectodomain of human FcalphaRI. J Biol Chem, 278, 27966-27970. PubMed id: 12783876 DOI: 10.1074/jbc.C300223200

Date:

21-Apr-03 Release date: 22-Jul-03

Protein chain

P24071  (FCAR_HUMAN) -  Immunoglobulin alpha Fc receptor from Homo sapiens

Seq: 287 a.a.

Struc: 191 a.a.

DOI no: 10.1074/jbc.C300223200

J Biol Chem 278:27966-27970 (2003)

PubMed id: 12783876

Crystal structure of the ectodomain of human FcalphaRI.

Y.Ding, G.Xu, M.Yang, M.Yao, G.F.Gao, L.Wang, W.Zhang, Z.Rao.

ABSTRACT

Human FcalphaRI (CD89) is the receptor specific for IgA, an immunoglobulin that is abundant in mucosa and is also found in high concentrations in serum. Although FcalphaRI is an immunoglobulin Fc receptor (FcR), it differs in many ways from FcRs for other immunoglobulin classes. The genes of most FcRs are located on chromosome 1 at 1q21-23, whereas FcalphaRI is on chromosome 19, at 19q13.4, a region called the leukocyte receptor complex, because it is clustered with several leukocyte receptor families including killer cell inhibitory receptors (KIRs) and leukocyte Ig-like receptors (LIRs). The amino acid sequence of FcalphaRI shares only 20% homology with other FcRs but it has around 35% homology with its neighboring LIRs and KIRs. In this work, we analyzed the crystal structure of the ectodomain of FcalphaRI and examined structure similarities between FcalphaRI and KIR2DL1, KIR2DL2 and LIR-1. Our data show that FcalphaRI, KIRs, and LIRs share a common hydrophobic core in their interdomain interface, and FcalphaRI is evolutionally closer to LIR than KIR.

Selected figure(s)

Figure 1.
FIG. 1. Crystal structure of Fc RI ectodomain. a, stereo ribbon drawing of the structure of Fc RI. EC1 is the N-terminal domain, and EC2 is the C-terminal domain. Disulfide bonds are shown in green. The residues 56-59 and 196-199 were disordered in the electron density map. b, topological diagram of the ectodomain of Fc RI. The arrows show the directions of -strands, whereas the 3[10] helix structures are represented by two circles. The amino acid residues at each end of -strands and helices are numbered. c, close-up stereo view of the hydrophobic core in the interdomain interface of Fc RI. The 12 residues responsible for stabilizing the hydrophobic core are shown in ball-and-stick representation. Tyr173 (Y173) is colored yellow, Tyr181 (Y181) blue, and Trp183 (W183) green. Other residues are colored using the CPK (Corey-Pauling-Kendrew) convention (blue, nitrogen; red, oxygen; gray, carbon; yellow, sulfur) color scheme.

Figure 4.
FIG. 4. Residues involved in Fc RI binding of IgA. a, position of the potential binding area on Fc RI. b, molecular surface of Fc RI. The residues involved in binding of IgA are highlighted in color. Tyr35 is colored red, Asn44 brown, Arg52 pink, Arg82 blue, Ile^83 green, Gly84 dark blue, His85 orange, and Tyr87 purple. The structure was represented by DeepView Swiss-PdbViewer (34).

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2003, 278, 27966-27970) copyright 2003.

Figures were selected by an automated process.