PDBsum entry 3h4z

Allergen

PDB id: 3h4z

Contents

Protein chains

568 a.a. *

Ligands

GLC-GLC ×3

Metals

_NA

Waters ×322

* Residue conservation analysis

PDB id:

3h4z

Name:

Allergen

Title:

Crystal structure of an mbp-der p 7 fusion protein

Structure:

Maltose-binding periplasmic protein fused with allergen derp7. Chain: a, b, c. Engineered: yes

Source:

Escherichia coli, dermatophagoides pteronyssinus. Organism_taxid: 562, 6956. Gene: male, derp7. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.35Å R-factor: 0.249 R-free: 0.293

Authors:

L.C.Pedersen,G.A.Mueller,R.E.London

Key ref:

G.A.Mueller et al. (2010). The structure of the dust mite allergen Der p 7 reveals similarities to innate immune proteins. J Allergy Clin Immunol, 125, 909. PubMed id: 20226507

Date:

21-Apr-09 Release date: 31-Mar-10

Protein chains

P0AEX9  (MALE_ECOLI) -  Maltose/maltodextrin-binding periplasmic protein from Escherichia coli (strain K12)

Seq: 396 a.a.

Struc: 568 a.a.*

Protein chains

P49273  (ALL7_DERPT) -  Mite allergen Der p 7 from Dermatophagoides pteronyssinus

Seq: 215 a.a.

Struc: 568 a.a.*

* PDB and UniProt seqs differ at 25 residue positions (black crosses)

J Allergy Clin Immunol 125:909 (2010)

PubMed id: 20226507

The structure of the dust mite allergen Der p 7 reveals similarities to innate immune proteins.

G.A.Mueller, L.L.Edwards, J.J.Aloor, M.B.Fessler, J.Glesner, A.Pomés, M.D.Chapman, R.E.London, L.C.Pedersen.

ABSTRACT

BACKGROUND: Sensitization to house dust mite allergens is strongly correlated with asthma. Der p 7 elicits strong IgE antibody and T-cell responses in patients with mite allergy. However, the structure and biological function of this important allergen are unknown. Allergen function might contribute to allergenicity, as shown for the protease activity of group 1 mite allergens and the interaction with the innate immune system by group 2 mite allergens. OBJECTIVE: We sought to determine the crystal structure of Der p 7 and to investigate its biological function. METHODS: X-ray crystallography was used to determine the Der p 7 structure. Nuclear magnetic resonance analysis and biochemical assays were used to examine the binding of Der p 7 to predicted ligands. RESULTS: Der p 7 has an elongated structure, with two 4-stranded antiparallel beta-sheets that wrap around a long C-terminal helix. The fold of Der p 7 is similar to that of LPS-binding protein (LBP), which interacts with Toll-like receptors after binding LPS and other bacterially derived lipid ligands. Nuclear magnetic resonance and biochemical assays indicate that Der p 7 does not bind LPS but binds with weak affinity to the bacterial lipopeptide polymyxin B in the predicted binding site of Der p 7. CONCLUSIONS: Der p 7 binds a bacterially derived lipid product, a common feature of some allergens. The finding that the group 7, as well as the group 2, mite allergens are structurally similar to different proteins in the Toll-like receptor pathway further strengthens the connections between dust mites, innate immunity, and allergy.