9SLD: GABA-A a4b3d receptor

GABA-A a4b3d receptor in complex with DS2-Me, GABA, Nb24 and Mb30. Determined by electron microscopy at 3.04 Å resolution. Released 2 Sept 2026.

Method: Electron microscopy
Resolution: 3.04 Å
Organisms: Homo sapiens, Escherichia coli, Lama glama
Chains: 9
Atoms: 17,506
Mol. weight: 298.83 kDa
Ligands: ABU, NAG, A1JOJ, D10
Released: 2 Sept 2026

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

Secondary structure: helices and β-sheets

9SLD contains 66 α-helices and 129 β-strands across 9 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: 12 helices, 18 β-strands

Element	Residues	Length	Sheet
α-helix	12-21	10
α-helix	36	1
β-strand	37-42	6	1
β-strand	43-44	2	2
β-strand	45-47	3	1
β-strand	48	1	3
β-strand	51-52	2	1
β-strand	57-69	13	1
β-strand	81-84	4	1
α-helix	88-91	4
β-strand	97-99	3	4
β-strand	102	1	1
β-strand	106-107	2	1
β-strand	115-120	6	1
β-strand	124-136	13	1
β-strand	148-157	10	4
β-strand	165-169	5	1
β-strand	177-178	2	2
α-helix	181-183	3
β-strand	184	1	3
β-strand	189-202	14	4
β-strand	207-219	13	4
α-helix	222-224	3
α-helix	225-229	5
α-helix	230-240	11
α-helix	241-243	3
α-helix	250-270	21
α-helix	281-282	2
α-helix	283-309	27
α-helix	313-415	31

Chain B: 11 helices, 20 β-strands

Element	Residues	Length	Sheet
α-helix	9-20	12
α-helix	35	1
β-strand	36-46	11	5
β-strand	50-51	2	5
β-strand	56-68	13	5
α-helix	70-72	3
β-strand	73	1	6
β-strand	81-83	3	5
α-helix	85-89	5
β-strand	96-98	3	7
β-strand	101-106	6	5
β-strand	110	1	8
β-strand	114	1	9
β-strand	116-118	3	5
β-strand	123-126	4	5
β-strand	128	1	9
β-strand	129-135	7	5
β-strand	147	1	10
β-strand	150-156	7	7
β-strand	164-168	5	5
α-helix	171-173	3
β-strand	175-176	2	5
β-strand	188-200	13	7
β-strand	203-214	12	7
β-strand	215	1	10
α-helix	218-221	4
α-helix	222-226	5
α-helix	227-241	15
α-helix	247-269	23
α-helix	280-306	27
α-helix	419-446	28

Chain C: 12 helices, 15 β-strands

Element	Residues	Length	Sheet
α-helix	12-21	10
α-helix	29	1
β-strand	37-47	11	11
β-strand	51-52	2	11
β-strand	57-69	13	11
α-helix	71-73	3
β-strand	81-84	4	11
α-helix	88-91	4
β-strand	97-99	3	8
β-strand	102	1	11
β-strand	106-107	2	11
β-strand	115	1	11
β-strand	117-120	4	11
β-strand	124-136	13	11
α-helix	141-143	3
β-strand	148-157	10	8
β-strand	165-169	5	11
β-strand	177-178	2	11
β-strand	189-203	15	8
β-strand	206-219	14	8
α-helix	222-224	3
α-helix	225-229	5
α-helix	230-240	11
α-helix	241-243	3
α-helix	250-269	20
α-helix	283-311	29
α-helix	313-416	32

Chain D: 12 helices, 15 β-strands

Element	Residues	Length	Sheet
α-helix	9-19	11
α-helix	35	1
β-strand	36-51	16	12
β-strand	56-68	13	12
α-helix	70-72	3
β-strand	73	1	13
β-strand	81-83	3	12
α-helix	85-89	5
β-strand	96-98	3	14
β-strand	101	1	12
β-strand	105-106	2	12
β-strand	114	1	12
β-strand	116-118	3	12
β-strand	123-135	13	12
α-helix	140-142	3
β-strand	147-156	10	14
β-strand	164-168	5	12
α-helix	171-173	3
β-strand	175-176	2	12
β-strand	186-200	15	14
β-strand	203-216	14	14
α-helix	219-221	3
α-helix	222-226	5
α-helix	227-241	15
α-helix	247-269	23
α-helix	280-306	27
α-helix	419-446	28

Chain E: 10 helices, 13 β-strands

Element	Residues	Length	Sheet
α-helix	20-24	5
α-helix	39	1
β-strand	40-45	6	15
β-strand	48-55	8	15
β-strand	60-72	13	15
α-helix	74-76	3
β-strand	85-87	3	15
α-helix	91-94	4
β-strand	100-102	3	16
β-strand	105-110	6	15
β-strand	114	1	4
β-strand	118-122	5	15
β-strand	127-139	13	15
β-strand	153-160	8	16
β-strand	168-172	5	15
α-helix	176-179	4
β-strand	190-200	11	16
β-strand	212-221	10	16
α-helix	228-242	15
α-helix	243-246	4
α-helix	252-276	25
α-helix	285-310	26
α-helix	315-415	29

Chain F: 2 helices, 10 β-strands

Element	Residues	Length	Sheet
β-strand	3-7	5	17
β-strand	405-412	8	17
α-helix	416-418	3
β-strand	419-426	8	18
β-strand	432-438	7	18
β-strand	446-448	3	18
β-strand	457-461	5	17
β-strand	466-471	6	17
α-helix	476-478	3
β-strand	480-488	9	18
β-strand	506-507	2	18
β-strand	511-513	3	18

Chain G: 4 helices, 15 β-strands

Element	Residues	Length	Sheet
β-strand	5-7	3	19
β-strand	11-13	3	20
β-strand	19-23	5	19
β-strand	34-38	5	21
β-strand	46-51	6	21
β-strand	58-60	3	21
β-strand	68-73	6	19
β-strand	78-83	6	19
α-helix	88-90	3
β-strand	92-95	4	21
β-strand	97	1	22
β-strand	102	1	6
α-helix	112	1
β-strand	113	1	22
α-helix	114	1
β-strand	115	1	19
α-helix	116	1
β-strand	117-119	3	21
β-strand	120-122	3	20

Chain H: 2 helices, 10 β-strands

Element	Residues	Length	Sheet
β-strand	3-7	5	23
β-strand	407-412	6	23
α-helix	416-418	3
β-strand	419-426	8	24
β-strand	432-438	7	24
β-strand	446-448	3	24
β-strand	456-461	6	23
β-strand	466-471	6	23
α-helix	476-478	3
β-strand	480-488	9	24
β-strand	506-507	2	24
β-strand	511-513	3	24

1 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
Gamma-aminobutyric acid receptor subunit alpha-4	A, C	protein	364	Homo sapiens	P48169 (AlphaFold model)
Gamma-aminobutyric acid receptor subunit beta-3,Soluble cytochrome b562	B, D	protein	451	Homo sapiens, Escherichia coli	P0ABE7 (AlphaFold model), P28472 (AlphaFold model)
Gamma-aminobutyric acid receptor subunit delta	E	protein	430	Homo sapiens	O14764 (AlphaFold model)
Megabody Mb30	F, H	protein	138	Lama glama
Nanobody Nb24	G, I	protein	133	Lama glama

Sequence of entity 1 (A, C), FASTA

>9SLD_1 Gamma-aminobutyric acid receptor subunit alpha-4 (chains A, C)
GNSKDEKLCPENFTRILDSLLDGYDNRLRPGFGGPVTEVKTDIYVTSFGPVSDVEMEYTM
DVFFRQTWIDKRLKYDGPIEILRLNNMMVTKVWTPDTFFRNGKKSVSHNMTAPNKLFRIT
RNGTILYTMRLTISAECPMRLVDFPMDGHACPLKFGSYAYPKSEMIYTWTKGPEKSVEVP
KESSSLVQYDLIGQTVSSETIKSITGEYIVMTVYFHLRRKMGYFMIQTYIPCIMTVILSQ
VSFWINKESVPARTVFGITTVLTMTTLSISARHSLPKVSYATAMDWFIAVCFAFVFSALI
EFAAVNYFTNSQPARAAKIDKYARILFPVTFGAFNMVYWVVYLSKDTMEKSESLMGTKHH
HHHH

Sequence of entity 2 (B, D), FASTA

>9SLD_2 Gamma-aminobutyric acid receptor subunit beta-3,Soluble cytochrome b562 (chains B, D)
QSVNDPGNMSFVKETVDKLLKGYDIRLRPDFGGPPVCVGMNIDIASIDMVSEVNMDYTLT
MYFQQYWRDKRLAYSGIPLNLTLDNRVADQLWVPDTYFLNDKKSFVHGVTVKNRMIRLHP
DGTVLYGLRITTTAACMMDLRRYPLDEQNCTLEIESYGYTTDDIEFYWRGGDKAVTGVER
IELPQFSIVEHRLVSRNVVFATGAYPRLSLSFRLKRNIGYFILQTYMPSILITILSWVSF
WINYDASAARVALGITTVLTMTTINTHLRETLPKIPYVKAIDMYLMGCFVFVFLALLEYA
FVNYIFFSQPAGTADLEDNWETLNDNLKVIEKADNAAQVKDALTKMRAAALDAQKATPPK
LEDKSPDSPEMKDFRHGFDILVGQIDDALKLANEGKVKEAQAAAEQLKTTRNAYIQKYLT
GRAAAIDRWSRIVFPFTFSLFNLVYWLYYVN

Sequence of entity 3 (E), FASTA

>9SLD_3 Gamma-aminobutyric acid receptor subunit delta (chains E)
MGILPSPGMPALLSLVSLLSVLLMGCVAEMDEKTTGWRGGHVVEGLAGELEQLRARLEHH
PQGQREPDYDIPTTENLYFQGTGAMNDIGDYVGSNLEISWLPNLDGLIAGYARNFRPGIG
GPPVNVALALEVASIDHISEANMEYTMTVFLHQSWRDSRLSYNHTNETLGLDSRFVDKLW
LPDTFIVNAKSAWFHDVTVENKLIRLQPDGVILYSIRITSTVACDMDLAKYPMDEQECML
DLESYGYSSEDIVYYWSESQEHIHGLDKLQLAQFTITSYRFTTELMNFKSAGQFPRLSLH
FHLRRNRGVYIIQSYMPSVLLVAMSWVSFWISQAAVPARVSLGITTVLTMTTLMVSARSS
LPRASAIKALDVYFWICYVFVFAALVEYAFAHFNADSQPARAATIDIYARAVFPAAFAAV
NVIYWAAYAM

Sequence of entity 4 (F, H), FASTA

>9SLD_4 Megabody Mb30 (chains F, H)
QVQLQESGGGLVQGSLRLSCTASQLTFSNYHMAWFRQLPGKEREFVAAISAGWGGNTAYG
TSIRGRFTISRDDAKNTAYLQMNSLKPEDTAVYYCAARNAVRPSWFAVKQTESAYDYWGQ
GTQVTVSSHHHHHHEPEA

Sequence of entity 5 (G, I), FASTA

>9SLD_5 Nanobody Nb24 (chains G, I)
QVQLQESGGGLVQAGDSLRLSCAASGRSIRNYHMGWFRQAPGKERDFVAAILWSGSSTFY
ADSVKGRFTVSRDNAKNTVYLQMNSLKPEDTAVYYCALHRGGSEDSPQAYDSWGQGTQVT
VSSHHHHHHEPEA

Ligands and cofactors

ID	Name	Formula	Copies
ABU	Gamma-amino-butanoic acid	C4 H9 N O2	2
NAG	2-acetamido-2-deoxy-beta-D-glucopyranose	C8 H15 N O6	6
A1JOJ	4-chloranyl-~{N}-(6-methyl-2-thiophen-2-yl-imidazo[1,2-a]pyridin-3-yl)benzamide	C19 H14 Cl N3 O S	1
D10	Decane	C10 H22	4

Primary citation

Molecular arrangement and modulation of extrasynaptic alpha beta delta GABA A receptors. Nestorow, S.A., Chen, W.N., Bertrand, D. et al. Nat Commun (2026) 17. DOI 10.1038/s41467-026-76879-5 · PubMed

Other PDB entries of the same protein (UniProt P48169 (AlphaFold model), which also has an AlphaFold model), best resolution first:

7QN5 2.5 Å, Cryo-EM structure of human full-length extrasynaptic alpha4beta3delta GABA(A)R in…
9SL1 2.68 Å, GABA-A a4b3d receptor in complex with GABA, Nb24 and Mb30
7QN9 2.9 Å, Cryo-EM structure of human full-length extrasynaptic alpha4beta3delta GABA(A)R in…
7QNC 2.9 Å, Cryo-EM structure of human full-length extrasynaptic alpha4beta3delta GABA(A)R in…
7QN7 3.0 Å, Cryo-EM structure of human full-length extrasynaptic alpha4beta3delta GABA(A)R in…
7QNA 3.0 Å, Cryo-EM structure of human full-length alpha4beta3gamma2 GABA(A)R in complex with GABA…

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