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 9XAS | pdb_00009xas

Crystal Structure of Sensory Appendage Protein (AgSAP2) mutant from Anopheles gambiae


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.31 Å
  • R-Value Free: 
    0.199 (Depositor), 0.199 (DCC) 
  • R-Value Work: 
    0.173 (Depositor), 0.173 (DCC) 
  • R-Value Observed: 
    0.176 (Depositor) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

Validation slider image for 9XAS

This is version 1.0 of the entry. See complete history. 

Literature

Structural Insights into Pyrethroid Recognition by Anopheles Chemosensory Proteins.

Biswas, S., Manickam, Y., Khai, C.Y., Goswami, R., Sukla, S., Barbosa, R., Sung, S., Chaturvedi, R., Marquez, J.A., Chaki, A., Sharma, A., Das, R., Sivaraman, J., Chakraborti, S.

(2026) ACS Infect Dis 

  • DOI: https://doi.org/10.1021/acsinfecdis.6c00114
  • Primary Citation Related Structures: 
    9XAS

  • PubMed Abstract: 

    Mosquito-borne diseases, particularly malaria, remain a major global health challenge. Among different mosquitoes, Anopheles are solely responsible for malaria. Insecticide-based interventions such as insecticide-treated nets (ITNs) and indoor residual spraying (IRS) are central to mosquito control. However, the widespread emergence of insecticide resistance, especially to pyrethroids, the most commonly used insecticides for mosquito worldwide, threatens their effectiveness. While genetic and metabolic mechanisms of resistance are well characterized, behavioral and sequestration-based mechanisms, particularly those involving chemosensory proteins (CSPs), are less understood. CSPs and odorant-binding proteins (OBPs) are integral components of the mosquito olfactory system, mediating host-seeking and other behavioral processes by transporting odorant molecules to olfactory receptors. Recent evidence suggests that CSPs may also bind insecticides like pyrethroids, contributing to resistance through sequestration. In this study, we investigated the structural and functional roles of CSPs in Anopheles mosquitoes. We determined three high-resolution X-ray crystal structures (apo-form) of CSPs (<2 Å) from Anopheles culicifacies and Anopheles gambiae, representing the first crystal structures of CSPs from any Anopheles species reported to date. Using structural, biophysical and computational approaches, we assessed CSP-ligand recognition of various insecticides, specifically pyrethroids and identified key residues potentially involved in pyrethroid interaction through site-directed mutagenesis. The moderate micromolar binding affinities of deltamethrin and permethrin, compared to other insecticides, support the role of CSPs in pyrethroid sequestration. Our findings offer mechanistic insights into pyrethroid sequestration and provide a foundation for developing novel vector control strategies that target CSP-insecticide interactions to combat pyrethroid resistance.


  • Organizational Affiliation: 
    • ICMR-National Institute of Malaria Research (NIMR) , Dwarka, New Delhi110077, India.

Macromolecule Content 

  • Total Structure Weight: 14.45 kDa 
  • Atom Count: 894 
  • Modeled Residue Count: 97 
  • Deposited Residue Count: 127 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
AGAP008052-PA127Anopheles gambiaeMutation(s): 6 
Gene Names: SAP-2, 1277898, AgaP_AGAP008052
UniProt
Find proteins for Q6H8Z3 (Anopheles gambiae)
Explore Q6H8Z3 
Go to UniProtKB:  Q6H8Z3
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ6H8Z3
Sequence Annotations
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Reference Sequence

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.31 Å
  • R-Value Free:  0.199 (Depositor), 0.199 (DCC) 
  • R-Value Work:  0.173 (Depositor), 0.173 (DCC) 
  • R-Value Observed: 0.176 (Depositor) 
Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 34.562α = 90
b = 44.319β = 90
c = 54.834γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling
PHENIXphasing

Structure Validation

View Full Validation Report



Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Ministry of Education (MoE, Singapore)Singapore--

Revision History  (Full details and data files)

  • Version 1.0: 2026-10-28
    Type: Initial release