Structure of Anopheles gambiae odorant binding protein 20 bound to polyethylene glycol

Experimental Data Snapshot

  • Resolution: 1.80 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.199 

wwPDB Validation   3D Report Full Report

This is version 1.2 of the entry. See complete history


A novel mechanism of ligand binding and release in the odorant binding protein 20 from the malaria mosquito Anopheles gambiae.

Ziemba, B.P.Murphy, E.J.Edlin, H.T.Jones, D.N.

(2013) Protein Sci 22: 11-21

  • DOI: https://doi.org/10.1002/pro.2179
  • Primary Citation of Related Structures:  
    3V2L, 3VB1, 4F7F

  • PubMed Abstract: 

    Anopheles gambiae mosquitoes that transmit malaria are attracted to humans by the odor molecules that emanate from skin and sweat. Odorant binding proteins (OBPs) are the first component of the olfactory apparatus to interact with odorant molecules, and so present potential targets for preventing transmission of malaria by disrupting the normal olfactory responses of the insect. AgamOBP20 is one of a limited subset of OBPs that it is preferentially expressed in female mosquitoes and its expression is regulated by blood feeding and by the day/night light cycles that correlate with blood-feeding behavior. Analysis of AgamOBP20 in solution reveals that the apo-protein exhibits significant conformational heterogeneity but the binding of odorant molecules results in a significant conformational change, which is accompanied by a reduction in the conformational flexibility present in the protein. Crystal structures of the free and bound states reveal a novel pathway for entrance and exit of odorant molecules into the central-binding pocket, and that the conformational changes associated with ligand binding are a result of rigid body domain motions in α-helices 1, 4, and 5, which act as lids to the binding pocket. These structures provide new insights into the specific residues involved in the conformational adaptation to different odorants and have important implications in the selection and development of reagents targeted at disrupting normal OBP function.

  • Organizational Affiliation

    Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
AGAP005208-PA120Anopheles gambiaeMutation(s): 0 
Gene Names: AgaP_AGAP005208OBP20
Find proteins for Q7Q9J3 (Anopheles gambiae)
Explore Q7Q9J3 
Go to UniProtKB:  Q7Q9J3
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ7Q9J3
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on PG4

Download Ideal Coordinates CCD File 
C8 H18 O5
Experimental Data & Validation

Experimental Data

  • Resolution: 1.80 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.199 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 34.577α = 90
b = 38.229β = 90
c = 89.912γ = 90
Software Package:
Software NamePurpose
d*TREKdata scaling
d*TREKdata reduction
PDB_EXTRACTdata extraction
Blu-Icedata collection

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-10-17
    Type: Initial release
  • Version 1.1: 2012-11-07
    Changes: Database references
  • Version 1.2: 2012-12-26
    Changes: Database references