22EM: Gi bound kappa-opioid receptor

Gi bound kappa-opioid receptor in complex with beta01. Determined by electron microscopy at 2.86 Å resolution. Released 6 May 2026.

Method: Electron microscopy
Resolution: 2.86 Å
Organisms: Homo sapiens, Mus musculus, Bos taurus
Chains: 5
Atoms: 7,138
Mol. weight: 159.38 kDa
Released: 6 May 2026

Explore 22EM in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

22EM contains 34 α-helices and 36 β-strands across 4 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 B: 11 helices, 8 β-strands

Element	Residues	Length	Sheet
α-helix	7-30	24
β-strand	34-40	7	1
α-helix	47-54	8
β-strand	185-191	7	1
β-strand	194-200	7	1
α-helix	208-210	3
α-helix	213-215	3
β-strand	220-226	7	1
α-helix	227-230	4
α-helix	232	1
β-strand	233	1	2
α-helix	234	1
β-strand	241	1	2
α-helix	242-254	13
β-strand	263-269	7	1
α-helix	271-278	8
α-helix	296-308	13
β-strand	319-323	5	1
α-helix	331-350	20

Chain C: 4 helices, 28 β-strands

Element	Residues	Length	Sheet
α-helix	8-25	18
α-helix	30-33	4
α-helix	38-39	2
β-strand	47-51	5	3
β-strand	58-63	6	4
β-strand	69-74	6	4
β-strand	78-83	6	4
β-strand	89-94	6	4
β-strand	100-105	6	5
β-strand	111-116	6	5
β-strand	121-125	5	5
β-strand	134-138	5	5
β-strand	146-151	6	6
β-strand	156-161	6	6
β-strand	166-170	5	6
β-strand	176-180	5	6
β-strand	187-190	4	7
β-strand	198-203	6	7
β-strand	207-212	6	7
β-strand	220-223	4	7
β-strand	229-234	6	8
β-strand	240-245	6	8
β-strand	250-254	5	8
β-strand	260-264	5	8
β-strand	273-278	6	9
β-strand	284-289	6	9
β-strand	294-298	5	9
β-strand	304-308	5	9
α-helix	309-310	2
β-strand	315-320	6	3
β-strand	327-331	5	3
β-strand	336-339	4	3

Chain D: 5 helices, 0 β-strands

Element	Residues	Length
α-helix	10-22	13
α-helix	30-44	15
α-helix	49-51	3
α-helix	53-55	3
α-helix	56-58	3

Chain F: 14 helices, 0 β-strands

Element	Residues	Length
α-helix	60-86	27
α-helix	93-109	17
α-helix	112-121	10
α-helix	128-161	34
α-helix	163-169	7
α-helix	172-195	24
α-helix	216-218	3
α-helix	219-231	13
α-helix	232-236	5
α-helix	237-253	17
α-helix	263-299	37
α-helix	307-309	3
α-helix	311-329	19
α-helix	335-341	7

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Guanine nucleotide-binding protein G(i) subunit alpha-1	B	protein	353	Homo sapiens	P63096 (AlphaFold model)
Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1	C	protein	371	Mus musculus	P62874 (AlphaFold model)
Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2	D	protein	71	Bos taurus	P63212 (AlphaFold model)
Soluble cytochrome b562,Kappa-type opioid receptor	F	protein	624	Escherichia coli, Homo sapiens	P0ABE7 (AlphaFold model), P41145
A1E3Y-phe-leu-dly-A1L9X	A	protein	5	synthetic construct

Sequence of entity 1 (B), FASTA

>22EM_1 Guanine nucleotide-binding protein G(i) subunit alpha-1 (chains B)
GCTLSAEDKAAVERSKMIDRNLREDGEKAAREVKLLLLGAGESGKSTIVKQMKIIHEAGY
SEEECKQYKAVVYSNTIQSIIAIIRAMGRLKIDFGDSARADDARQLFVLAGAAEEGFMTA
ELAGVIKRLWKDSGVQACFNRSREYQLNDSAAYYLNDLDRIAQPNYIPTQQDVLRTRVKT
TGIVETHFTFKDLHFKMFDVGAQRSERKKWIHCFEGVTAIIFCVALSDYDLVLAEDEEMN
RMHESMKLFDSICNNKWFTDTSIILFLNKKDLFEEKIKKSPLTICYPEYAGSNTYEEAAA
YIQCQFEDLNKRKDTKEIYTHFTCSTDTKNVQFVFDAVTDVIIKNNLKDCGLF

Sequence of entity 2 (C), FASTA

>22EM_2 Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1 (chains C)
HHHHHHGSLLQLRQEAEQLKNQIRDARKACADATLSQITNNIDPVGRIQMRTRRTLRGHL
AKIYAMHWGTDSRLLVSASQDGKLIIWDSYTTNKVHAIPLRSSWVMTCAYAPSGNYVACG
GLDNICSIYNLKTREGNVRVSRELAGHTGYLSCCRFLDDNQIVTSSGDTTCALWDIETGQ
QTTTFTGHTGDVMSLSLAPDTRLFVSGACDASAKLWDVREGMCRQTFTGHESDINAICFF
PNGNAFATGSDDATCRLFDLRADQELMTYSHDNIICGITSVSFSKSGRLLLAGYDDFNCN
VWDALKADRAGVLAGHDNRVSCLGVTDDGMAVATGSWDSFLKIWNGSSGGGGSGGGGSSG
VSGWRLFKKIS

Sequence of entity 3 (D), FASTA

>22EM_3 Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2 (chains D)
MASNNTASIAQARKLVEQLKMEANIDRIKVSKAAADLMAYCEAHAKEDPLLTPVPASENP
FREKKFFCAIL

Sequence of entity 4 (F), FASTA

>22EM_4 Soluble cytochrome b562,Kappa-type opioid receptor (chains F)
MKTIIALSYIFCLVFADYKDDDDKADLEDNWETLNDNLKVIEKADNAAQVKDALTKMRAA
ALDAQKATPPKLEDKSPDSPEMKDFRHGFDILVGQIDDALKLANEGKVKEAQAAAEQLKT
TRNAYIQKYLENLYFQGMGQPGNGSAFLLAPNRSHAPDHDVISPAIPVIITAVYSVVFVV
GLVGNSLVMFVIIRYTKMKTATNIYIFNLALADALVTTTMPFQSTVYLMNSWPFGDVLCK
IVISIDYYNMFTSIFTLTMMSVDRYIAVCHPVKALDFRTPLKAKIINICIWLLSSSVGIS
AIVLGGTKVREDVDVIECSLQFPDDDYSWWDLFMKICVFIFAFVIPVLIIIVCYTLMILR
LKSVRLLSGSREKDRNLRRITRLVLVVVAVFVVCWTPIHIFILVEALGSTSHSTAALSSY
YFCIALGYTNSSLNPILYAFLDENFKRCFRDFCFPLKMRMERQSTSVFTLEDFVGDWEQT
AAYNLDQVLEQGGVSSLLQNLAVSVTPIQRIVRSGENALKIDIHVIIPYEGLSADQMAQI
EEVFKVVYPVDDHHFKVILPYGTLVIDGVTPNMLNYFGRPYEGIAVFDGKKITVTGTLWN
GNKIIDERLITPDGSMLFRVTINS

Sequence of entity 5 (A), FASTA

>22EM_5 A1E3Y-PHE-LEU-DLY-A1L9X (chains A)
XFLKX

Primary citation

Gi bound kappa-opioid receptor in complex with beta01. Zhang, H., Wang, R., Shi, P. et al. To be published.

Other PDB entries of the same protein (UniProt P63096 (AlphaFold model), which also has an AlphaFold model), best resolution first:

6CRK 2.0 Å, Heterotrimeric G-protein in complex with an antibody fragment
3UMR 2.04 Å, Crystal structure of the G202D mutant of human G-alpha-i1
9P7Z 2.1 Å, NTSR1-Gi-NTS(8-13) Complex in the Canonical, AHD Open State (C-Open-Apo)
2OM2 2.2 Å, Crystal Structure Of Human G[alpha]i1 Bound To The Goloco Motif Of Rgs14
8YN9 2.3 Å, Cryo-EM structure of histamine H4 receptor in complex with histamine and Gi
9HYI 2.3 Å, DP81-bound serotonin 5-HT1A receptor - Gi Protein Complex
9O36 2.3 Å, CryoEM structure of mu-opioid receptor - Gi protein complex bound to fluornitrazene (FNZ)
9P80 2.3 Å, NTSR1-Gi-NTS(8-13) Complex in the Non-Canonical, AHD Open State (NC-Open-Apo)
8XXV 2.33 Å, Cryo-EM Structure of the Prostaglandin D2 Receptor 2-indomethacin Coupled to G Protein
3UMS 2.34 Å, Crystal structure of the G202A mutant of human G-alpha-i1
3ONW 2.38 Å, Structure of a G-alpha-i1 mutant with enhanced affinity for the RGS14 GoLoco motif.
20ZG 2.4 Å, Cryo-EM structure of the human neurotensin receptor 1 (hNTSR1)-Gi1 complex in the…

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