6B73 image
Entry Detail
PDB ID:
6B73
Title:
Crystal Structure of a nanobody-stabilized active state of the kappa-opioid receptor
Biological Source:
PDB Version:
Deposition Date:
2017-10-03
Release Date:
2018-01-17
Method Details:
Experimental Method:
Resolution:
3.10 Å
R-Value Free:
0.27
R-Value Work:
0.25
R-Value Observed:
0.25
Space Group:
P 1 21 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Soluble cytochrome b562, kappa-type opioid receptor
Mutations:M29W, H124I, L51R, I135L
Chain IDs:A, B
Chain Length:418
Number of Molecules:2
Biological Source:Escherichia coli, Homo sapiens
Polymer Type:polypeptide(L)
Description:Nanobody
Chain IDs:C, D
Chain Length:134
Number of Molecules:2
Biological Source:Lama glama
Primary Citation

Abstact

The κ-opioid receptor (KOP) mediates the actions of opioids with hallucinogenic, dysphoric, and analgesic activities. The design of KOP analgesics devoid of hallucinatory and dysphoric effects has been hindered by an incomplete structural and mechanistic understanding of KOP agonist actions. Here, we provide a crystal structure of human KOP in complex with the potent epoxymorphinan opioid agonist MP1104 and an active-state-stabilizing nanobody. Comparisons between inactive- and active-state opioid receptor structures reveal substantial conformational changes in the binding pocket and intracellular and extracellular regions. Extensive structural analysis and experimental validation illuminate key residues that propagate larger-scale structural rearrangements and transducer binding that, collectively, elucidate the structural determinants of KOP pharmacology, function, and biased signaling. These molecular insights promise to accelerate the structure-guided design of safer and more effective κ-opioid receptor therapeutics.

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