25ST | pdb_000025st

cryo-EM structure of human TAS2R4 with amino acids

• PDB DOI: https://doi.org/10.2210/pdb25ST/pdb
• Entry: 25ST supersedes: 9M8K
• EM Map EMD-63712: EMDB EMDataResource

• Classification: MEMBRANE PROTEIN
• Organism(s): Homo sapiens, Mus musculus
• Expression System: Spodoptera frugiperda
• Mutation(s): No 


• Deposited: 2026-04-16 Released: 2026-06-24 
• Deposition Author(s): Tan, M., Wu, J.
• Funding Organization(s): National Science Foundation (NSF, China)

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.00 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Receptor hyper-flexibility of human bitter receptor TAS2R4 revealed by cryo-EM structures in apo and tripeptide-bound states

Tan, M., Wu, J.

To be published.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 6-mer - A1B1C1D1E1F1 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 148.19 kDa 
• Atom Count: 8,992 
• Modeled Residue Count: 1,147 
• Deposited Residue Count: 1,332 
• Unique protein chains: 6

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Guanine nucleotide-binding protein G(i) subunit alpha-1,Guanine nucleotide-binding protein G(t) subunit alpha-3	A	239	Homo sapiens	Mutation(s): 0  Gene Names: GNAI1, GNAT3 EC: 3.6.5
UniProt & NIH Common Fund Data Resources
Find proteins for P63096 (Homo sapiens) Explore P63096  Go to UniProtKB:  P63096
PHAROS:  P63096 GTEx:  ENSG00000127955
Find proteins for A8MTJ3 (Homo sapiens) Explore A8MTJ3  Go to UniProtKB:  A8MTJ3
PHAROS:  A8MTJ3 GTEx:  ENSG00000214415
UniProt Groups	P63096A8MTJ3

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-3	B	351	Homo sapiens	Mutation(s): 0  Gene Names: GNB3
UniProt & NIH Common Fund Data Resources
Find proteins for P16520 (Homo sapiens) Explore P16520  Go to UniProtKB:  P16520
PHAROS:  P16520 GTEx:  ENSG00000111664

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-13	C [auth G]	67	Homo sapiens	Mutation(s): 0  Gene Names: GNG13
UniProt & NIH Common Fund Data Resources
Find proteins for Q9P2W3 (Homo sapiens) Explore Q9P2W3  Go to UniProtKB:  Q9P2W3
PHAROS:  Q9P2W3 GTEx:  ENSG00000127588

Entity ID: 4
Molecule	Chains	Sequence Length	Organism	Details	Image
Single-chain variable fragment 16	D [auth N]	307	Mus musculus	Mutation(s): 0

Entity ID: 5
Molecule	Chains	Sequence Length	Organism	Details	Image
Taste receptor type 2 member 4	E [auth R]	365	Homo sapiens	Mutation(s): 0  Gene Names: TAS2R4
UniProt & NIH Common Fund Data Resources
Find proteins for Q9NYW5 (Homo sapiens) Explore Q9NYW5  Go to UniProtKB:  Q9NYW5
PHAROS:  Q9NYW5 GTEx:  ENSG00000127364

Entity ID: 6
Molecule	Chains	Sequence Length	Organism	Details	Image
TRP-TRP-TRP	F [auth S]	3	Homo sapiens	Mutation(s): 0

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.00 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
MODEL REFINEMENT	PHENIX	1.21.2_5419
RECONSTRUCTION	cryoSPARC

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2026-06-24 
Deposition Author(s): Tan, M., Wu, J.
• This entry supersedes: 9M8K

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Funding Organization	Location	Grant Number
National Science Foundation (NSF, China)	China	--

Revision History  

• Version 1.0: 2026-06-24
  Type: Initial release