2ERB

AgamOBP1, and odorant binding protein from Anopheles gambiae complexed with PEG

Summary for 2ERB

• Entry DOI: 10.2210/pdb2erb/pdb
• Descriptor: odorant binding protein, MAGNESIUM ION, 2,5,8,11,14,17,20,23,26,29,32,35,38,41,44,47,50,53,56,59,62,65,68,71,74,77,80-HEPTACOSAOXADOOCTACONTAN-82-OL, ... (4 entities in total)
• Functional Keywords: helix, disulfides, transport protein
• Biological source: Anopheles gambiae (African malaria mosquito)
• Total number of polymer chains: 2
• Total formula weight: 30341.00

Authors

Wogulis, M.,Morgan, T.,Ishida, Y.,Leal, W.S.,Wilson, D.K. (deposition date: 2005-10-24, release date: 2005-12-13, Last modification date: 2024-11-20)

Primary citation

Wogulis, M.,Morgan, T.,Ishida, Y.,Leal, W.S.,Wilson, D.K.
The crystal structure of an odorant binding protein from Anopheles gambiae: Evidence for a common ligand release mechanism.
Biochem.Biophys.Res.Commun., 339:157-164, 2006

PubMed Abstract: The Anopheles gambiae mosquito is the main vector of malaria transmission in sub-Saharan Africa. We present here a 1.5A crystal structure of AgamOBP1, an odorant binding protein (OBP) from the A. gambiae mosquito. The protein crystallized as a dimer with a unique binding pocket consisting of a continuous tunnel running through both subunits of the dimer and occupied by a PEG molecule. We demonstrate that AgamOBP1 undergoes a pH dependent conformational change that is associated with reduced ligand binding. A predominance of acid-labile hydrogen bonds involving the C-terminal loop suggests a mechanism in which a drop in pH causes C-terminal loop to open, leaving the binding tunnel solvent exposed, thereby lowering binding affinity for ligand. Because proteins from two distantly related insects also undergo a pH dependent conformational change involving the C-terminus that is associated with reduced ligand affinity, our results suggest a common mechanism for OBP activity.

PubMed: 16300742
DOI: 10.1016/j.bbrc.2005.10.191

Experimental method

X-RAY DIFFRACTION (1.5 Å)