9WYD | pdb_00009wyd

Crystal structure of HAstV8 spike and FcRn

• PDB DOI: https://doi.org/10.2210/pdb9WYD/pdb

• Classification: VIRAL PROTEIN
• Organism(s): Homo sapiens, Human astrovirus 8
• Expression System: Baculovirus expression vector pFastBac1-HM, Escherichia coli
• Mutation(s): No 


• Deposited: 2025-09-26 Released: 2026-02-11 
• Deposition Author(s): Wang, W., Xu, Y., Zhang, S.J.
• Funding Organization(s): National Natural Science Foundation of China (NSFC)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.65 Å
• R-Value Free: 
  0.232 (Depositor), 0.233 (DCC) 
• R-Value Work: 
  0.187 (Depositor), 0.187 (DCC) 
• R-Value Observed: 
  0.189 (Depositor) 

Starting Models: experimental

Literature

The conserved human astrovirus-receptor interface reveals a targetable vulnerability for antiviral development.

Wang, W., Xu, Y., Li, Z., Liu, D., Ma, K., Wang, R., Chen, R., Shu, B., Sun, X., Liu, Y., Ke, X., Zhang, S.

(2026) Nat Commun 17

• PubMed: 41813687 
• DOI: https://doi.org/10.1038/s41467-026-70465-5
• Primary Citation Related Structures: 
  9WYD, 9WYE, 9WYG


• PubMed Abstract: 
  

  Human astrovirus (HAstV) is a major cause of viral enteritis in children and the older adults worldwide. The eight serotypes of classical HAstVs (HAstV1-8), employ the neonatal Fc receptor (FcRn) as an entry receptor. To elucidate the receptor binding mechanism of HAstVs, we determined the crystal structure of the HAstV8 spike protein complexed with human FcRn. The structure reveals that the HAstV8 spike protein engaged FcRn via a conserved surface depression, which is also present across the other seven classical HAstVs serotypes. The binding interface of HAstV8 spike protein on FcRn largely overlaps with the footprints of three clinically approved FcRn blockers to treat an autoimmune disease. Accordingly, these FcRn inhibitors potently suppress astrovirus infection, significantly reducing viral RNA levels in astrovirus permissive Caco2 cells. Therefore, our study reports a conserved receptor recognition mechanism among human astroviruses and suggests the potential of repurposing clinically approved therapeutics to treat astrovirus infection.

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Organizational Affiliation: 
• College of Life Sciences, Nanjing Agricultural University, Nanjing, China.
Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology Ministry of Agriculture, Nanjing, China.
State Key Laboratory of Virology and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China.
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases (NITFID), NHC Key Laboratory for Medical Virology and Viral Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China. [e-mail].
State Key Laboratory for Diagnosis and Treatment of Infectious Diseases of the First Affiliated Hospital and Department of Microbiology, Zhejiang University School of Medicine, Hangzhou, China. [e-mail].
State Key Laboratory of Virology and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China. [e-mail].
College of Life Sciences, Nanjing Agricultural University, Nanjing, China. [e-mail].

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 3-mer - A1B1C1 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: surface plasmon resonance

Macromolecule Content 

• Total Structure Weight: 68.3 kDa 
• Atom Count: 4,581 
• Modeled Residue Count: 568 
• Deposited Residue Count: 605 
• Unique protein chains: 3

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
IgG receptor FcRn large subunit p51	A	274	Homo sapiens	Mutation(s): 0  Gene Names: FCGRT, FCRN
UniProt & NIH Common Fund Data Resources
Find proteins for P55899 (Homo sapiens) Explore P55899  Go to UniProtKB:  P55899
PHAROS:  P55899 GTEx:  ENSG00000104870

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Beta-2-microglobulin	B	99	Homo sapiens	Mutation(s): 0  Gene Names: B2M, CDABP0092, HDCMA22P
UniProt & NIH Common Fund Data Resources
Find proteins for P61769 (Homo sapiens) Explore P61769  Go to UniProtKB:  P61769
PHAROS:  P61769 GTEx:  ENSG00000166710

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
Spike protein VP27	C	232	Human astrovirus 8	Mutation(s): 0  Gene Names: ORF2
UniProt
Find proteins for Q9IFX1 (Human astrovirus-8) Explore Q9IFX1  Go to UniProtKB:  Q9IFX1

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.65 Å
• R-Value Free:  0.232 (Depositor), 0.233 (DCC) 
• R-Value Work:  0.187 (Depositor), 0.187 (DCC) 
• R-Value Observed: 0.189 (Depositor) 

Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 173.12	α = 90
b = 84.429	β = 97.42
c = 53.953	γ = 90

Software Package:

Software Name	Purpose
PHENIX	refinement
XDS	data reduction
XDS	data scaling
PHASER	phasing

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2026-02-11 
Deposition Author(s): Wang, W., Xu, Y., Zhang, S.J.

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Funding Organization	Location	Grant Number
National Natural Science Foundation of China (NSFC)	China	32170158

Revision History  

• Version 1.0: 2026-02-11
  Type: Initial release
  
• Version 1.1: 2026-09-16
  Changes: Database references