9PPX: Delta opioid receptor

CryoEM structure of delta opioid receptor bound to G proteins and naltrexone. Determined by electron microscopy at 3.04 Å resolution. Released 4 Mar 2026.

Method: Electron microscopy
Resolution: 3.04 Å
Organisms: Homo sapiens, Mus musculus
Chains: 5
Atoms: 6,894
Mol. weight: 146.3 kDa
Ligands: A1CLJ
Released: 4 Mar 2026

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

Secondary structure: helices and β-sheets

9PPX contains 24 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: 13 helices, 2 β-strands

Element	Residues	Length	Sheet
α-helix	51-72	22
α-helix	73-77	5
α-helix	83-111	29
α-helix	118-151	34
α-helix	153-159	7
α-helix	162-186	25
β-strand	188-191	4	1
β-strand	196-199	4	1
α-helix	209-218	10
α-helix	219-223	5
α-helix	224-242	19
α-helix	256-282	27
α-helix	296-312	17
α-helix	314-321	8
α-helix	323-326	4

Chain B: 2 helices, 6 β-strands

Element	Residues	Length	Sheet
α-helix	7-30	24
β-strand	33-39	7	2
β-strand	185-191	7	2
β-strand	194-200	7	2
β-strand	220-224	5	2
β-strand	263-267	5	2
β-strand	319-322	4	2
α-helix	330-351	22

Chain C: 4 helices, 28 β-strands

Element	Residues	Length	Sheet
α-helix	18-25	8
α-helix	30-33	4
α-helix	38-40	3
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	88-94	7	4
β-strand	100-105	6	5
β-strand	111-116	6	5
β-strand	121-125	5	5
β-strand	134-139	6	5
β-strand	146-151	6	6
β-strand	156-161	6	6
β-strand	165-170	6	6
β-strand	175-180	6	6
β-strand	187-192	6	7
β-strand	198-203	6	7
β-strand	208-212	5	7
β-strand	218-222	5	7
β-strand	229-234	6	8
β-strand	240-245	6	8
β-strand	249-254	6	8
β-strand	259-264	6	8
α-helix	272	1
β-strand	273-278	6	9
β-strand	284-289	6	9
β-strand	293-298	6	9
β-strand	303-307	5	9
β-strand	315-320	6	3
β-strand	327-331	5	3
β-strand	336-339	4	3

Chain D: 2 helices, 0 β-strands

Element	Residues	Length	Sheet
α-helix	30-43	14
α-helix	53-55	3

Chain E: 3 helices, 24 β-strands

Element	Residues	Length	Sheet
β-strand	3-6	4	10
β-strand	10-12	3	11
β-strand	18-25	8	10
β-strand	33-39	7	11
β-strand	45-51	7	11
α-helix	53-55	3
β-strand	58-60	3	11
β-strand	68-73	6	10
β-strand	78-83	6	10
β-strand	92-99	8	11
β-strand	110-111	2	11
β-strand	115-119	5	11
β-strand	128-129	2	12
β-strand	135-136	2	13
β-strand	143-149	7	12
β-strand	154	1	14
β-strand	160	1	14
β-strand	162-167	6	15
β-strand	174-179	6	15
β-strand	182-183	2	15
β-strand	191-196	6	12
β-strand	199-204	6	12
α-helix	209-211	3
β-strand	214-219	6	15
α-helix	230	1
β-strand	231-232	2	15
β-strand	233-234	2	13

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Delta-type opioid receptor	A	protein	303	Homo sapiens	P41143 (AlphaFold model)
Guanine nucleotide-binding protein G(i) subunit alpha-1	B	protein	354	Homo sapiens	P63096 (AlphaFold model)
Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1	C	protein	340	Homo sapiens	P62873 (AlphaFold model)
Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2	D	protein	71	Homo sapiens	P59768 (AlphaFold model)
ScFv16 protein	E	protein	251	Mus musculus

Sequence of entity 1 (A), FASTA

>9PPX_1 Delta-type opioid receptor (chains A)
GSPGARSASSLALAIAITALYSAVCAVGLLGNVLVMFGIVRYTKMKTATNIYIFNLALAD
ALATSTLPFQSAKYLMETWPFGELLCKAVLSIDYYNMFTSIFTLTMMSVDRYIAVCHPVK
ALDFRTPAKAKLINICIWVLASGVGVPIMVMAVTRPRDGAVVCMLQFPSPSWYWDTVTKI
CVFLFAFVVPILIITVCYGLMLLRLRSVRLLSGSKEKDRSLRRITRMVLVVVGAFVVCWA
PIHIFVIVWTLVDIDRRDPLVVAALHLCIALGYANSSLNPVLYAFLDENFKRCFRQLCRK
PCG

Sequence of entity 2 (B), FASTA

>9PPX_2 Guanine nucleotide-binding protein G(i) subunit alpha-1 (chains B)
MGCTLSAEDKAAVERSKMIDRNLREDGEKAAREVKLLLLGAGESGKNTIVKQMKIIHEAG
YSEEECKQYKAVVYSNTIQSIIAIIRAMGRLKIDFGDSARADDARQLFVLAGAAEEGFMT
AELAGVIKRLWKDSGVQACFNRSREYQLNDSAAYYLNDLDRIAQPNYIPTQQDVLRTRVK
TTGIVETHFTFKDLHFKMFDVGAQRSERKKWIHCFEGVTAIIFCVALSDYDLVLAEDEEM
NRMHASMKLFDSICNNKWFTDTSIILFLNKKDLFEEKIKKSPLTICYPEYAGSNTYEEAA
AYIQCQFEDLNKRKDTKEIYTHFTCSTDTKNVQFVFDAVTDVIIKNNLKDCGLF

Sequence of entity 3 (C), FASTA

>9PPX_3 Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1 (chains C)
GSELDQLRQEAEQLKNQIRDARKACADATLSQITNNIDPVGRIQMRTRRTLRGHLAKIYA
MHWGTDSRLLVSASQDGKLIIWDSYTTNKVHAIPLRSSWVMTCAYAPSGNYVACGGLDNI
CSIYNLKTREGNVRVSRELAGHTGYLSCCRFLDDNQIVTSSGDTTCALWDIETGQQTTTF
TGHTGDVMSLSLAPDTRLFVSGACDASAKLWDVREGMCRQTFTGHESDINAICFFPNGNA
FATGSDDATCRLFDLRADQELMTYSHDNIICGITSVSFSKSGRLLLAGYDDFNCNVWDAL
KADRAGVLAGHDNRVSCLGVTDDGMAVATGSWDSFLKIWN

Sequence of entity 4 (D), FASTA

>9PPX_4 Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2 (chains D)
MASNNTASIAQARKLVEQLKMEANIDRIKVSKAAADLMAYCEAHAKEDPLLTPVPASENP
FREKKFFCAIL

Sequence of entity 5 (E), FASTA

>9PPX_5 ScFv16 protein (chains E)
DVQLVESGGGLVQPGGSRKLSCSASGFAFSSFGMHWVRQAPEKGLEWVAYISSGSGTIYY
ADTVKGRFTISRDDPKNTLFLQMTSLRSEDTAMYYCVRSIYYYGSSPFDFWGQGTTLTVS
SGGGGSGGGGSGGGGSDIVMTQATSSVPVTPGESVSISCRSSKSLLHSNGNTYLYWFLQR
PGQSPQLLIYRMSNLASGVPDRFSGSGSGTAFTLTISRLEAEDVGVYYCMQHLEYPLTFG
AGTKLELKAAA

Ligands and cofactors

ID	Name	Formula	Copies
A1CLJ	17-(cyclopropylmethyl)-3,14-dihydroxy-5alpha-4,5-epoxymorphinan-6-one	C20 H23 N O4	1

Primary citation

Mechanistic insights into the therapeutic properties of delta opioid receptor. Bernhard, S.M., Roy Chowdhury, S., Murata, T. et al. Sci Adv (2026) 12:eaeb6737-eaeb6737. DOI 10.1126/sciadv.aeb6737 · PubMed

Other PDB entries of the same protein (UniProt P41143 (AlphaFold model), which also has an AlphaFold model), best resolution first:

4N6H 1.8 Å, 1.8 A Structure of the human delta opioid 7TM receptor (PSI Community Target)
9YDP 1.95 Å, Human delta opioid receptor complex with mini-Gi and agonist DADLE
9CGK 2.62 Å, CryoEM structure of delta opioid receptor bound to G proteins and a full bitopic agonist
4RWD 2.7 Å, XFEL structure of the human delta opioid receptor in complex with a bifunctional peptide
9XDQ 2.79 Å, Cryo-EM structure of BMS986187 bound DOR-Gi complex
6PT2 2.8 Å, Crystal structure of the active delta opioid receptor in complex with the peptide…
9CGJ 2.8 Å, CryoEM structure of delta opioid receptor bound to G proteins and a partial agonist
8Y71 2.97 Å, positive allosteric modulator(BMS986187)-bound delta-opioid receptor-Gi complex
8F7S 3.0 Å, Gi bound delta-opioid receptor in complex with deltorphin
9XF4 3.05 Å, Cryo-EM structure of Leu-enkephalin-BMS-986187-bound DOR-Gi2 complex
9PPY 3.1 Å, CryoEM structure of delta opioid receptor bound to G proteins and met-enkephalin
9PQ0 3.12 Å, CryoEM structure of delta opioid receptor bound to G proteins and ADL5859

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