9O36: Mu-opioid receptor - Gi protein complex

CryoEM structure of mu-opioid receptor - Gi protein complex bound to fluornitrazene (FNZ). Determined by electron microscopy at 2.3 Å resolution. Released 1 Apr 2026.

Method: Electron microscopy
Resolution: 2.3 Å
Organisms: Homo sapiens, Mus musculus
Chains: 5
Atoms: 8,330
Mol. weight: 162.06 kDa
Ligands: A1B79
Released: 1 Apr 2026

Explore 9O36 in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9O36 contains 36 α-helices and 60 β-strands across 5 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: 10 helices, 6 β-strands

Element	Residues	Length	Sheet
α-helix	7-30	24
β-strand	34-40	7	1
α-helix	46-52	7
β-strand	185-191	7	1
β-strand	194-200	7	1
α-helix	208-210	3
α-helix	212-215	4
β-strand	220-226	7	1
α-helix	242-254	13
α-helix	257-259	3
β-strand	263-269	7	1
α-helix	272-278	7
α-helix	283-285	3
α-helix	296-308	13
β-strand	319-323	5	1
α-helix	330-350	21

Chain B: 3 helices, 28 β-strands

Element	Residues	Length	Sheet
α-helix	7-25	19
α-helix	30-33	4
α-helix	38-39	2
β-strand	47-51	5	2
β-strand	58-63	6	3
β-strand	69-74	6	3
β-strand	78-83	6	3
β-strand	89-94	6	3
β-strand	100-105	6	4
β-strand	111-116	6	4
β-strand	121-125	5	4
β-strand	134-139	6	4
β-strand	146-153	8	5
β-strand	156-161	6	5
β-strand	166-170	5	5
β-strand	175-180	6	5
β-strand	187-192	6	6
β-strand	198-203	6	6
β-strand	208-212	5	6
β-strand	218-222	5	6
β-strand	229-234	6	7
β-strand	240-245	6	7
β-strand	250-254	5	7
β-strand	259-264	6	7
β-strand	273-278	6	8
β-strand	284-289	6	8
β-strand	294-298	5	8
β-strand	303-308	6	8
β-strand	315-320	6	2
β-strand	327-331	5	2
β-strand	336-339	4	2

Chain C: 3 helices, 0 β-strands

Element	Residues	Length
α-helix	10-23	14
α-helix	30-43	14
α-helix	45-47	3

Chain E: 5 helices, 24 β-strands

Element	Residues	Length	Sheet
β-strand	3-7	5	9
β-strand	10-12	3	10
β-strand	17-25	9	9
α-helix	29-31	3
β-strand	33-39	7	10
β-strand	45-51	7	10
β-strand	58-60	3	10
β-strand	68-73	6	9
β-strand	78-84	7	9
α-helix	88-90	3
β-strand	92-99	8	10
β-strand	110-111	2	10
β-strand	115-119	5	10
β-strand	128-129	2	11
β-strand	134-136	3	12
β-strand	143-149	7	11
β-strand	154	1	13
β-strand	160	1	13
β-strand	162-167	6	12
β-strand	174-178	5	12
β-strand	182-183	2	12
α-helix	184	1
β-strand	191-195	5	11
β-strand	199-204	6	11
α-helix	209-211	3
β-strand	214-219	6	12
α-helix	225	1
β-strand	226-227	2	12
β-strand	231-234	4	12

Chain R: 15 helices, 2 β-strands

Element	Residues	Length	Sheet
α-helix	66-95	30
α-helix	102-118	17
α-helix	121-130	10
α-helix	137-170	34
α-helix	172-175	4
α-helix	181-194	14
α-helix	196-203	8
β-strand	206-210	5	14
β-strand	215-219	5	14
α-helix	225-237	13
α-helix	238-242	5
α-helix	243-259	17
α-helix	263-265	3
α-helix	270-303	34
α-helix	312-331	20
α-helix	333-336	4
α-helix	342-344	3

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Guanine nucleotide-binding protein G(i) subunit alpha-1	A	protein	354	Homo sapiens	P63096 (AlphaFold model)
Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1	B	protein	344	Homo sapiens	P62873 (AlphaFold model)
Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2	C	protein	71	Homo sapiens	P59768 (AlphaFold model)
scFv16	E	protein	259	Mus musculus
Mu-type opioid receptor	R	protein	426	Mus musculus	P42866 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>9O36_1 Guanine nucleotide-binding protein G(i) subunit alpha-1 (chains A)
MGCTLSAEDKAAVERSKMIDRNLREDGEKAAREVKLLLLGAGESGKSTIVKQMKIIHEAG
YSEEECKQYKAVVYSNTIQSIIAIIRAMGRLKIDFGDSARADDARQLFVLAGAAEEGFMT
AELAGVIKRLWKDSGVQACFNRSREYQLNDSAAYYLNDLDRIAQPNYIPTQQDVLRTRVK
TTGIVETHFTFKDLHFKMFDVGGQRSERKKWIHCFEGVTAIIFCVALSDYDLVLAEDEEM
NRMHESMKLFDSICNNKWFTDTSIILFLNKKDLFEEKIKKSPLTICYPEYAGSNTYEEAA
AYIQCQFEDLNKRKDTKEIYTHFTCATDTKNVQFVFDAVTDVIIKNNLKDCGLF

Sequence of entity 2 (B), FASTA

>9O36_2 Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1 (chains B)
PGSSGSELDQLRQEAEQLKNQIRDARKACADATLSQITNNIDPVGRIQMRTRRTLRGHLA
KIYAMHWGTDSRLLVSASQDGKLIIWDSYTTNKVHAIPLRSSWVMTCAYAPSGNYVACGG
LDNICSIYNLKTREGNVRVSRELAGHTGYLSCCRFLDDNQIVTSSGDTTCALWDIETGQQ
TTTFTGHTGDVMSLSLAPDTRLFVSGACDASAKLWDVREGMCRQTFTGHESDINAICFFP
NGNAFATGSDDATCRLFDLRADQELMTYSHDNIICGITSVSFSKSGRLLLAGYDDFNCNV
WDALKADRAGVLAGHDNRVSCLGVTDDGMAVATGSWDSFLKIWN

Sequence of entity 3 (C), FASTA

>9O36_3 Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2 (chains C)
MASNNTASIAQARKLVEQLKMEANIDRIKVSKAAADLMAYCEAHAKEDPLLTPVPASENP
FREKKFFCAIL

Sequence of entity 4 (E), FASTA

>9O36_4 scFv16 (chains E)
DVQLVESGGGLVQPGGSRKLSCSASGFAFSSFGMHWVRQAPEKGLEWVAYISSGSGTIYY
ADTVKGRFTISRDDPKNTLFLQMTSLRSEDTAMYYCVRSIYYYGSSPFDFWGQGTTLTVS
SGGGGSGGGGSGGGGSDIVMTQATSSVPVTPGESVSISCRSSKSLLHSNGNTYLYWFLQR
PGQSPQLLIYRMSNLASGVPDRFSGSGSGTAFTLTISRLEAEDVGVYYCMQHLEYPLTFG
AGTKLELKAAAHHHHHHHH

Sequence of entity 5 (R), FASTA

>9O36_5 Mu-type opioid receptor (chains R)
MKTIIALSYIFCLVFADYKDDDDAMGPGNISDCSDPLAPASCSPAPGSWLNLSHVDGNQS
DPCGPNRTGLGGSHSLCPQTGSPSMVTAITIMALYSIVCVVGLFGNFLVMYVIVRYTKMK
TATNIYIFNLALADALATSTLPFQSVNYLMGTWPFGNILCKIVISIDYYNMFTSIFTLCT
MSVDRYIAVCHPVKALDFRTPRNAKIVNVCNWILSSAIGLPVMFMATTKYRQGSIDCTLT
FSHPTWYWENLLKICVFIFAFIMPVLIITVCYGLMILRLKSVRMLSGSKEKDRNLRRITR
MVLVVVAVFIVCWTPIHIYVIIKALITIPETTFQTVSWHFCIALGYTNSCLNPVLYAFLD
ENFKRCFREFCIPTSSTIEQQNSARIRQNTREHPSTANTVDRTNHQLENLEAETAPLPDI
HHHHHH

Ligands and cofactors

ID	Name	Formula	Copies
A1B79	N,N-diethyl-2-(2-{[4-(2-fluoroethoxy)phenyl]methyl}-5-nitro-1H-1,3-benzimidazol…	C22 H27 F N4 O3	1

Primary citation

A μ-opioid receptor superagonist analgesic with minimal adverse effects. Gomez, J.L., Ventriglia, E.N., Frangos, Z.J. et al. Nature (2026) 652:1393-1404. DOI 10.1038/s41586-026-10299-9 · PubMed

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
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…
20ZH 2.4 Å, Cryo-EM structure of the human neurotensin receptor 1 (hNTSR1)-Gi1 complex in the…

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