1GT1: Complex Of Bovine Odorant Binding Protein With Aminoanthracene And Pyrazine

The structure of bovine odorant-binding protein (bOBP) revealed a striking feature of a dimer formed by domain swapping [Tegoni, M., Ramoni, R., Bignetti, E., Spinelli, S. & Cambillau, C. (1996) Nat. Struct. Biol.3, 863-867; Bianchet, M.A., Bains, G., Pelosi, P., Pevsner, J., Snyder, S.H., Monaco, H.L. & Amzel, L.M. (1996) Nat. Struct. Biol.3, 934-939] and the presence of a naturally occuring ligand [Ramoni, R., Vincent, F., Grolli, S., Conti, V., Malosse, C., Boyer, F.D., Nagnan-Le Meillour, P., Spinelli, S., Cambillau, C. & Tegoni, M. (2001) J. Biol. Chem.276, 7150-7155]. These features led us to investigate the binding of odorant molecules with bOBP in solution and in the crystal. The behavior of odorant molecules in bOBP resembles that observed with porcine OBP (pOBP), although the latter is monomeric and devoid of ligand when purified. The odorant molecules presented K(d) values with bOBP in the micromolar range. Most of the X-ray structures revealed that odorant molecules interact with a common set of residues forming the cavity wall and do not exhibit specific interactions. Depending on the ligand and on the monomer (A or B), a single residue--Phe89--presents alternate conformations and might control cross-talking between the subunits. Crystal data on both pOBP and bOBP, in contrast with binding and spectroscopic studies on rat OBP in solution, reveal an absence of significant conformational changes involving protein loops or backbone. Thus, the role of OBP in signal triggering remains unresolved.
PDB ID: 1GT1Download
MMDB ID: 72179
PDB Deposition Date: 2002/1/10
Updated in MMDB: 2011/12
Experimental Method:
x-ray diffraction
Resolution: 1.71  Å
Source Organism:
Similar Structures:
Biological Unit for 1GT1: dimeric; determined by author and by software (PISA)
Molecular Components in 1GT1
Label Count Molecule
Proteins (2 molecules)
Odorant-binding Protein(Gene symbol: OBP)
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB