9PA4: (S)-ketamine bound kappa-opioid receptor
(S)-ketamine bound kappa-opioid receptor in complex with Gi1. Determined by electron microscopy at 2.5 Å resolution. Released 1 Jul 2026.
- Method
- Electron microscopy
- Resolution
- 2.5 Å
- Organisms
- Homo sapiens, Mus musculus
- Chains
- 5
- Atoms
- 8,600
- Mol. weight
- 147.46 kDa
- Ligands
- JC9
- Released
- 1 Jul 2026
Explore 9PA4 in 3D
Show helices and sheets
RCSB PDB
PDBe
Secondary structure: helices and β-sheets
9PA4 contains 35 α-helices and 64 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: 11 helices, 2 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 59-86 | 28 | |
| α-helix | 93-120 | 28 | |
| α-helix | 128-161 | 34 | |
| α-helix | 166-169 | 4 | |
| α-helix | 172-195 | 24 | |
| β-strand | 198-200 | 3 | 1 |
| β-strand | 209-211 | 3 | 1 |
| α-helix | 219-231 | 13 | |
| α-helix | 232-236 | 5 | |
| α-helix | 237-253 | 17 | |
| α-helix | 264-299 | 36 | |
| α-helix | 302-304 | 3 | |
| α-helix | 306-330 | 25 | |
Chain B: 10 helices, 8 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 7-31 | 25 | |
| β-strand | 34-40 | 7 | 9 |
| α-helix | 46-54 | 9 | |
| β-strand | 185-191 | 7 | 9 |
| β-strand | 194-200 | 7 | 9 |
| α-helix | 208-210 | 3 | |
| α-helix | 212-215 | 4 | |
| β-strand | 220-226 | 7 | 9 |
| α-helix | 227-231 | 5 | |
| β-strand | 233 | 1 | 10 |
| β-strand | 241 | 1 | 10 |
| α-helix | 242-254 | 13 | |
| β-strand | 263-269 | 7 | 9 |
| α-helix | 271-280 | 10 | |
| α-helix | 283-285 | 3 | |
| α-helix | 296-309 | 14 | |
| β-strand | 319-323 | 5 | 9 |
| α-helix | 328-351 | 24 | |
Chain C: 3 helices, 28 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 3-25 | 23 | |
| 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 | 88-94 | 7 | 3 |
| β-strand | 100-105 | 6 | 4 |
| β-strand | 111-116 | 6 | 4 |
| β-strand | 120-125 | 6 | 4 |
| β-strand | 134-140 | 7 | 4 |
| β-strand | 146-151 | 6 | 5 |
| β-strand | 156-161 | 6 | 5 |
| β-strand | 165-170 | 6 | 5 |
| β-strand | 175-181 | 7 | 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 | 304-307 | 4 | 8 |
| β-strand | 315-320 | 6 | 2 |
| β-strand | 327-331 | 5 | 2 |
| β-strand | 336-339 | 4 | 2 |
Chain D: 3 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 8-23 | 16 | |
| α-helix | 30-43 | 14 | |
| α-helix | 53-55 | 3 | |
Chain E: 8 helices, 26 β-strands
| Element | Residues | Length | Sheet |
|---|
| β-strand | 3-6 | 4 | 11 |
| β-strand | 11-12 | 2 | 12 |
| β-strand | 18-25 | 8 | 11 |
| α-helix | 29-31 | 3 | |
| β-strand | 33-39 | 7 | 13 |
| β-strand | 45-51 | 7 | 13 |
| α-helix | 53-55 | 3 | |
| β-strand | 58-60 | 3 | 13 |
| α-helix | 62-64 | 3 | |
| β-strand | 68-73 | 6 | 11 |
| α-helix | 74-76 | 3 | |
| β-strand | 78-83 | 6 | 11 |
| α-helix | 88-90 | 3 | |
| β-strand | 92-99 | 8 | 13 |
| β-strand | 110-111 | 2 | 13 |
| β-strand | 115-117 | 3 | 13 |
| β-strand | 118-119 | 2 | 12 |
| β-strand | 128-129 | 2 | 14 |
| β-strand | 134-137 | 4 | 15 |
| β-strand | 143-149 | 7 | 14 |
| β-strand | 154 | 1 | 16 |
| β-strand | 160 | 1 | 16 |
| β-strand | 162-167 | 6 | 15 |
| β-strand | 174-178 | 5 | 15 |
| β-strand | 182-183 | 2 | 15 |
| α-helix | 184 | 1 | |
| β-strand | 191-195 | 5 | 14 |
| β-strand | 199-204 | 6 | 14 |
| α-helix | 209-211 | 3 | |
| β-strand | 214-219 | 6 | 15 |
| α-helix | 225 | 1 | |
| β-strand | 227 | 1 | 15 |
| β-strand | 228 | 1 | 14 |
| β-strand | 231-235 | 5 | 15 |
Molecules and chains
| Molecule | Chains | Type | Length | Organism | UniProt |
|---|
| Kappa-type opioid receptor | A | protein | 308 | Homo sapiens | P41145 (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) |
| Guanine nucleotide-binding protein G(i) subunit alpha-1 | B | protein | 354 | Homo sapiens | P63096 (AlphaFold model) |
| ScFv16 protein | E | protein | 251 | Mus musculus | |
Sequence of entity 1 (A), FASTA
>9PA4_1 Kappa-type opioid receptor (chains A)
LGSISPAIPVIITAVYSVVFVVGLVGNSLVMFVIIRYTKMKTATNIYIFNLALADALVTT
TMPFQSTVYLMNSWPFGDVLCKIVLSIDYYNMFTSIFTLTMMSVDRYIAVCHPVKALDFR
TPLKAKIINICIWLLSSSVGISAIVLGGTKVREDVDVIECSLQFPDDDYSWWDLFMKICV
FIFAFVIPVLIIIVCYTLMILRLKSVRLLSGSREKDRNLRRITRLVLVVVAVFVVCWTPI
HIFILVEALGSTSHSTAALSSYYFCIALGYTNSSLNPILYAFLDENFKRCFRDFCFPLKM
RMERQSTS
Sequence of entity 2 (C), FASTA
>9PA4_2 Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1 (chains C)
GSELDQLRQEAEQLKNQIRDARKACADATLSQITNNIDPVGRIQMRTRRTLRGHLAKIYA
MHWGTDSRLLVSASQDGKLIIWDSYTTNKVHAIPLRSSWVMTCAYAPSGNYVACGGLDNI
CSIYNLKTREGNVRVSRELAGHTGYLSCCRFLDDNQIVTSSGDTTCALWDIETGQQTTTF
TGHTGDVMSLSLAPDTRLFVSGACDASAKLWDVREGMCRQTFTGHESDINAICFFPNGNA
FATGSDDATCRLFDLRADQELMTYSHDNIICGITSVSFSKSGRLLLAGYDDFNCNVWDAL
KADRAGVLAGHDNRVSCLGVTDDGMAVATGSWDSFLKIWN
Sequence of entity 3 (D), FASTA
>9PA4_3 Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2 (chains D)
MASNNTASIAQARKLVEQLKMEANIDRIKVSKAAADLMAYCEAHAKEDPLLTPVPASENP
FREKKFFCAIL
Sequence of entity 4 (B), FASTA
>9PA4_4 Guanine nucleotide-binding protein G(i) subunit alpha-1 (chains B)
MGCTLSAEDKAAVERSKMIDRNLREDGEKAAREVKLLLLGAGESGKNTIVKQMKIIHEAG
YSEEECKQYKAVVYSNTIQSIIAIIRAMGRLKIDFGDSARADDARQLFVLAGAAEEGFMT
AELAGVIKRLWKDSGVQACFNRSREYQLNDSAAYYLNDLDRIAQPNYIPTQQDVLRTRVK
TTGIVETHFTFKDLHFKMFDVGAQRSERKKWIHCFEGVTAIIFCVALSDYDLVLAEDEEM
NRMHASMKLFDSICNNKWFTDTSIILFLNKKDLFEEKIKKSPLTICYPEYAGSNTYEEAA
AYIQCQFEDLNKRKDTKEIYTHFTCSTDTKNVQFVFDAVTDVIIKNNLKDCGLF
Sequence of entity 5 (E), FASTA
>9PA4_5 ScFv16 protein (chains E)
DVQLVESGGGLVQPGGSRKLSCSASGFAFSSFGMHWVRQAPEKGLEWVAYISSGSGTIYY
ADTVKGRFTISRDDPKNTLFLQMTSLRSEDTAMYYCVRSIYYYGSSPFDFWGQGTTLTVS
SGGGGSGGGGSGGGGSDIVMTQATSSVPVTPGESVSISCRSSKSLLHSNGNTYLYWFLQR
PGQSPQLLIYRMSNLASGVPDRFSGSGSGTAFTLTISRLEAEDVGVYYCMQHLEYPLTFG
AGTKLELKAAA
Ligands and cofactors
| ID | Name | Formula | Copies |
|---|
| JC9 | (2~{S})-2-(2-chlorophenyl)-2-(methylamino)cyclohexan-1-one | C13 H16 Cl N O | 1 |
Primary citation
Structural basis of opioid receptor activation by PCP and ketamine. Jiang, Q., Han, J., Fine, E.J. et al. Nat Struct Mol Biol (2026) 33:1341-1353. DOI 10.1038/s41594-026-01839-y · PubMed
Other PDB entries of the same protein (UniProt P41145 (AlphaFold model), which also has an AlphaFold model), best resolution first:
- 7UL2 2.4 Å, CryoEM Structure of Inactive NTSR1 Bound to SR48692 and Nb6
- 22ES 2.43 Å, Gi bound kappa-opioid receptor in complex with difelikefalin
- 7T10 2.5 Å, CryoEM structure of somatostatin receptor 2 in complex with somatostatin-14 and Gi3
- 8FEG 2.54 Å, CryoEM structure of Kappa Opioid Receptor bound to a semi-peptide and Gi1
- 9XDR 2.58 Å, Cryo-EM structure of asimadoline-BMS-986187-bound KOR-Gi1 complex
- 9ZZO 2.6 Å, MP1104-bound Kappa Opioid Receptor in complex with beta-arrestin1
- 8DZR 2.61 Å, GR89,696 bound Kappa Opioid Receptor in complex with gustducin
- 9PA1 2.63 Å, PCP bound kappa-opioid receptor in complex with Gi1
- 8DZS 2.65 Å, GR89,696 bound Kappa Opioid Receptor in complex with Gz
- 7T11 2.7 Å, CryoEM structure of somatostatin receptor 2 in complex with Octreotide and Gi3.
- 8DZP 2.71 Å, momSalB bound Kappa Opioid Receptor in complex with Gi1
- 9V6O 2.76 Å, Cryo-EM structure of human kappa opioid receptor - G protein signaling complex bound…
Browse structure collections
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