PDBsum entry 1e06

Odorant binding protein

PDB id: 1e06

Contents

Protein chains

149 a.a. *

Ligands

IPB ×2

Waters ×156

* Residue conservation analysis

PDB id:

1e06

Name:

Odorant binding protein

Title:

Porcine odorant binding protein complexed with 5-methyl-2-(1- methylethyl)phenol

Structure:

Odorant-binding protein. Chain: a, b. Synonym: pig obp

Source:

Sus scrofa. Pig. Organism_taxid: 9823. Organ: nose. Tissue: olfactory epithelium

Biol. unit:

Monomer (from PDB file)

Resolution:

2.12Å R-factor: 0.213 R-free: 0.255

Authors:

F.Vincent,S.Spinelli,C.Cambillau,M.Tegoni

Key ref:

F.Vincent et al. (2000). Complexes of porcine odorant binding protein with odorant molecules belonging to different chemical classes. J Mol Biol, 300, 127-139. PubMed id: 10864504 DOI: 10.1006/jmbi.2000.3820

Date:

10-Mar-00 Release date: 06-Dec-00

Protein chains

P81245  (OBP_PIG) -  Odorant-binding protein from Sus scrofa

Seq: 157 a.a.

Struc: 149 a.a.

DOI no: 10.1006/jmbi.2000.3820

J Mol Biol 300:127-139 (2000)

PubMed id: 10864504

Complexes of porcine odorant binding protein with odorant molecules belonging to different chemical classes.

F.Vincent, S.Spinelli, R.Ramoni, S.Grolli, P.Pelosi, C.Cambillau, M.Tegoni.

ABSTRACT

Porcine odorant binding protein (pOBP) is a monomer of 157 amino acid residues, purified in abundance from pig nasal mucosa. In contrast to the observation on lipocalins as retinol binding protein (RBP), major urinary protein (MUP) or bovine odorant binding protein (bOBP), no naturally occurring ligand was found in the beta-barrel cavity of pOBP. Porcine OBP was therefore chosen as a simple model for structure/function studies with odorant molecules. In competition experiments with tritiated pyrazine, the affinity of pOBP towards several odorant molecules belonging to different chemical classes has been found to be of the micromolar order, with a 1:1 stoichiometry. The X-ray structures of pOBP complexed to these molecules were determined at resolution between 2.15 and 1.4 A. As expected, the electron density of the odorant molecules was observed into the hydrophobic beta-barrel of the lipocalin. Inside this cavity, very few specific interactions were established between the odorant molecule and the amino acid side-chains, which did not undergo significant conformational change. The high B-factors observed for the odorant molecules as well as the existence of alternative conformations reveal a non-specific mode of binding of the odorant molecules in the cavity.

Selected figure(s)

Figure 3.
Figure 3. Overall view of porcine OBP in complex with BZB. The b-sheets of the b-barrel are colored in dark blue and the helix is in red. The odor is rep- resented in CPK, within the water-accessible surface cal- culated without odor molecule. The Figure has been prepared by TURBO-FRODO (Roussel & Cambillau, 1991).

Figure 5.
Figure 5. Stereo views of the side-chains of the residues of the cavity involved in the interaction with odors. All the complexes are superimposed. View (b) is rotated 90 ° with respect to view (a).

The above figures are reprinted by permission from Elsevier: J Mol Biol (2000, 300, 127-139) copyright 2000.

Figures were selected by an automated process.