9QTN: Human alpha7 nicotinic receptor

Human alpha7 nicotinic receptor in complex with the F1 nanobody. Determined by electron microscopy at 2.28 Å resolution. Released 18 Feb 2026.

Method: Electron microscopy
Resolution: 2.28 Å
Organisms: Homo sapiens, Vicugna pacos
Chains: 10
Atoms: 14,522
Mol. weight: 353.38 kDa
Released: 18 Feb 2026

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

Secondary structure: helices and β-sheets

9QTN contains 29 α-helices and 144 β-strands across 10 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: 2 helices, 15 β-strands

Element	Residues	Length	Sheet
α-helix	2-10	9
β-strand	28-43	16	1
β-strand	48-65	18	1
α-helix	68-70	3
β-strand	77-79	3	1
β-strand	89-91	3	2
β-strand	94	1	1
β-strand	102	1	1
β-strand	107-109	3	1
β-strand	112-117	6	1
β-strand	120-126	7	1
β-strand	138-147	10	2
β-strand	155-159	5	1
β-strand	163	1	1
β-strand	173-177	5	2
β-strand	180-186	7	2
β-strand	193-205	13	2

Chain B: 2 helices, 16 β-strands

Element	Residues	Length	Sheet
α-helix	2-10	9
α-helix	27	1
β-strand	28-43	16	3
β-strand	48-65	18	3
β-strand	76-79	4	3
β-strand	89-91	3	4
β-strand	94	1	3
β-strand	102	1	3
β-strand	107-110	4	3
β-strand	112-117	6	3
β-strand	120-126	7	3
β-strand	138-147	10	4
β-strand	155-159	5	3
β-strand	163	1	3
β-strand	168	1	3
β-strand	173-177	5	4
β-strand	180-186	7	4
β-strand	193-205	13	4

Chain C: 2 helices, 18 β-strands

Element	Residues	Length	Sheet
α-helix	2-9	8
β-strand	28-33	6	5
β-strand	35	1	6
β-strand	36-43	8	7
β-strand	48-54	7	7
β-strand	56-65	10	5
β-strand	77-79	3	5
β-strand	89-91	3	8
β-strand	94	1	7
β-strand	102	1	7
β-strand	107-109	3	5
β-strand	112-117	6	5
β-strand	120-126	7	7
β-strand	138-147	10	8
β-strand	155-159	5	5
α-helix	161-162	2
β-strand	163	1	6
β-strand	173-177	5	8
β-strand	180-185	6	8
β-strand	194-205	12	8

Chain D: 3 helices, 15 β-strands

Element	Residues	Length	Sheet
α-helix	2-9	8
α-helix	27	1
β-strand	28-43	16	9
β-strand	48-65	18	9
β-strand	77-79	3	9
β-strand	89-91	3	10
β-strand	94	1	9
β-strand	102	1	9
β-strand	107-109	3	9
β-strand	112-117	6	9
β-strand	120-126	7	9
β-strand	138-147	10	10
β-strand	155-159	5	9
α-helix	161-162	2
β-strand	163	1	9
β-strand	173-177	5	10
β-strand	180-186	7	10
β-strand	193-205	13	10

Chain E: 3 helices, 15 β-strands

Element	Residues	Length	Sheet
α-helix	2-10	9
α-helix	27	1
β-strand	28-43	16	11
β-strand	48-65	18	11
β-strand	76-79	4	11
β-strand	89-91	3	12
β-strand	94	1	11
β-strand	102	1	11
β-strand	107-110	4	11
β-strand	112-117	6	11
β-strand	120-126	7	11
β-strand	138-147	10	12
β-strand	155-159	5	11
β-strand	163	1	11
α-helix	167-170	4
β-strand	173-177	5	12
β-strand	180-186	7	12
β-strand	193-205	13	12

Chain F: 4 helices, 14 β-strands

Element	Residues	Length	Sheet
β-strand	5	1	13
β-strand	6-8	3	14
β-strand	12-13	2	15
β-strand	18-24	7	14
α-helix	30-33	4
α-helix	37	1
β-strand	38-43	6	16
β-strand	49-55	7	16
β-strand	62-64	3	16
β-strand	72-77	6	14
β-strand	82-88	7	14
α-helix	92-94	3
β-strand	96-103	8	16
α-helix	115-117	3
β-strand	118-121	4	16
β-strand	122	1	13
β-strand	125-127	3	16
β-strand	128-129	2	15

Chain G: 3 helices, 13 β-strands

Element	Residues	Length	Sheet
β-strand	6-8	3	17
β-strand	11-14	4	18
β-strand	18-24	7	17
α-helix	30-33	4
α-helix	36-37	2
β-strand	38-43	6	18
β-strand	50-55	6	18
β-strand	57	1	19
β-strand	59	1	19
β-strand	62-64	3	18
β-strand	72-77	6	17
β-strand	82-88	7	17
β-strand	96-102	7	18
α-helix	115-117	3
β-strand	120-121	2	18
β-strand	125-130	6	18

Chain H: 3 helices, 11 β-strands

Element	Residues	Length	Sheet
β-strand	6-8	3	20
β-strand	11-13	3	21
β-strand	18-24	7	20
α-helix	30-33	4
α-helix	36-37	2
β-strand	38-43	6	21
β-strand	49-55	7	21
β-strand	62-64	3	21
β-strand	72-77	6	20
β-strand	82-88	7	20
β-strand	96-102	7	21
α-helix	115-117	3
β-strand	120-121	2	21
β-strand	125-129	5	21

2 more chain groups are not listed. Open the entry in the viewer and use the sequence panel to see them.

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Neuronal acetylcholine receptor subunit alpha-7	A, B, C, D, E	protein	479	Homo sapiens	P36544 (AlphaFold model)
Nanobody F1	F, G, H, I, J	protein	131	Vicugna pacos

Sequence of entity 1 (A, B, C, D, E), FASTA

>9QTN_1 Neuronal acetylcholine receptor subunit alpha-7 (chains A, B, C, D, E)
EFQRKLYKELVKNYNPLERPVANDSQPLTVYFSLSLLQIMDVDEKNQVLTTNIWLQMSWT
DHYLQWNVSEYPGVKTVRFPDGQIWKPDILLYNSADERFDATFHTNVLVNSSGHCQYLPP
GIFKSSCYIDVRWFPFDVQHCKLKFGSWSYGGWSLDLQMQEADISGYIPNGEWDLVGIPG
KRSERFYECCKEPYPDVTFTVTMRRRTLYYGLNLLIPCVLISALALLVFLLPADSGEKIS
LGITVLLSLTVFMLLVAEIMPATSDSVPLIAQYFASTMIIVGLSVVVTVIVLQYHHHDPD
GGKMPKWTRVILLNWCAWFLRMKRPGEDKVRPACQHKQRRCSLASVEMSAVAPPPASNGN
LLYIGFRGLDGVHCVPTPDSGVVCGRMACSPTHDEHLLHGGQPPEGDPDLAKILEEVRYI
ANRFRCQDESEAVCSEWKFAACVVDRLCLMAFSVFTIICTIGILMSAPNFVEAVSKDFA

Sequence of entity 2 (F, G, H, I, J), FASTA

>9QTN_2 Nanobody F1 (chains F, G, H, I, J)
EVQLVESGGGLVQAGGSLRLSCAAPGITLSRYGMYGMGWFRQAPGKEREFVAAITWSGGQ
TYYQDSVKGRFTISRDNAKKLTFLQMNSLKPEDTAVYYCAADGDRFYPEPVVDDNAYKFW
GQGTQVTVSSA

Primary citation

Discovery and mechanism of negative allosteric modulation of the alpha 7 nicotinic acetylcholine receptor by nanobodies. Barilone, N., Vangelatou, M., Marouf, F.Z. et al. Proc Natl Acad Sci U S A (2026) 123:e2514734123-e2514734123. DOI 10.1073/pnas.2514734123 · PubMed

Other PDB entries of the same protein (UniProt P36544 (AlphaFold model), which also has an AlphaFold model), best resolution first:

8P1H 1.95 Å, Crystal structure of the chimera of human 14-3-3 zeta and phosphorylated cytoplasmic…
5AFN 2.15 Å, alpha7-AChBP in complex with lobeline and fragment 5
9QTO 2.16 Å, Human alpha7 nicotinic receptor in complex with the E6 nanobody
8V8A 2.19 Å, Alpha7-nicotinic acetylcholine receptor time resolved bound to epibatidine and…
5AFJ 2.2 Å, alpha7-AChBP in complex with lobeline and fragment 1
8C9X 2.3 Å, human alpha7 nicotinic receptor in complex with the C4 nanobody
8UT1 2.3 Å, Alpha7-nicotinic acetylcholine receptor bound to epibatidine
8UTB 2.3 Å, Alpha7-nicotinic acetylcholine receptor bound to epibatidine and NS-1738
8UZJ 2.3 Å, Alpha7-nicotinic acetylcholine receptor bound to epibatidine and ivermectin
8V88 2.3 Å, Alpha7-nicotinic acetylcholine receptor bound to epibatidine and GAT107
8V80 2.34 Å, Alpha7-nicotinic acetylcholine receptor bound to epibatidine and (-)-TQS
5AFK 2.38 Å, alpha7-AChBP in complex with lobeline and fragment 2

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