9IQR: MT3-alpha2AAR

Cryo-EM structure of MT3-alpha2AAR. Determined by electron microscopy at 3.4 Å resolution. Released 23 Jul 2025.

Method: Electron microscopy
Resolution: 3.4 Å
Organisms: Dendroaspis angusticeps, Homo sapiens, synthetic construct
Chains: 2
Atoms: 2,622
Mol. weight: 56.29 kDa
Released: 23 Jul 2025

Explore 9IQR in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9IQR contains 13 α-helices and 5 β-strands across 2 chains. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.

Chain A: 0 helices, 5 β-strands

Element	Residues	Length	Sheet
β-strand	3-7	5	1
β-strand	12-15	4	1
β-strand	23-32	10	2
β-strand	35-43	9	2
β-strand	55-58	4	2

Chain B: 13 helices, 0 β-strands

Element	Residues	Length
α-helix	47-73	27
α-helix	85-97	13
α-helix	102-111	10
α-helix	118-152	35
α-helix	153-155	3
α-helix	161-178	18
α-helix	181-186	6
α-helix	211-216	6
α-helix	217-221	5
α-helix	222-240	19
α-helix	383-414	32
α-helix	420-443	24
α-helix	446-453	8

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Muscarinic toxin 3	A	protein	65	Dendroaspis angusticeps	P81031 (AlphaFold model)
Alpha-2A adrenergic receptor,Soluble cytochrome b562	B	protein	433	Homo sapiens, synthetic construct	P08913 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>9IQR_1 Muscarinic toxin 3 (chains A)
LTCVTKNTIFGITTENCPAGQNLCFKRWHYVIPRYTEITRGCAATCPIPENYDSIHCCKT
DKCNE

Sequence of entity 2 (B), FASTA

>9IQR_2 Alpha-2A adrenergic receptor,Soluble cytochrome b562 (chains B)
ARATPYSLQVTLTLVCLAGLLMLLTVFGNVLVIIAVFTSRALKAPQNLFLVSLASADILV
ATLVIPFSLANEVMGYWYFGKAWCEIYLALDVLFCTSSIVHLCAISLDRYWSITQAIEYN
LKRTPRRIKAIIITVWVISAVISFPPLISIEKKGGGGGPQPAEPRCEINDQKWYVISSCI
GSFFAPCLIMILVYVRIYQIAKRRAADLEDNWETLNDNLKVIEKADNAAQVKDALTKMRA
AALDAQKASGSGSPEMKDFRHGFDILVGQIDDALKLANEGKVKEAQAAAEQLKTTRNAYI
QKYLAGRQNREKRFTFVLAVVIGVFVVCWFPFFFTYTLTAVGCSVPRTLFKFFFWFGYCN
SSLNPVIYTIFNHDFRRAFKKILKIAALKEKIAALKEKIAALKEAEEKRASRLEEELRRR
LTEGSHHHHHHHH

Primary citation

Structure-guided engineering of snake toxins for selective modulation of adrenergic and muscarinic receptors. Zhong, Y., Tao, H., Zhang, Y. et al. Nat Commun (2025) 16:6478-6478. DOI 10.1038/s41467-025-61695-0 · PubMed

Other PDB entries of the same protein (UniProt P81031 (AlphaFold model), which also has an AlphaFold model), best resolution first:

9IQV 3.3 Å, Cryo-EM structure of MT3-alpha1AAR
9IQS 3.6 Å, Cryo-EM structure of MT3-Muscarinic acetylcholine receptor 4

Browse structure collections

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