7BU6 image
Entry Detail
PDB ID:
7BU6
Title:
Structure of human beta1 adrenergic receptor bound to norepinephrine and nanobody 6B9
Biological Source:
PDB Version:
Deposition Date:
2020-04-04
Release Date:
2020-12-02
Method Details:
Experimental Method:
Resolution:
2.70 Å
R-Value Free:
0.25
R-Value Work:
0.23
R-Value Observed:
0.23
Space Group:
C 1 2 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Endolysin,Endolysin,Endolysin,Beta-1 adrenergic receptor chimera
Mutations:C944T,C987A
Chain IDs:A
Chain Length:516
Number of Molecules:1
Biological Source:Enterobacteria phage T4, Homo sapiens
Polymer Type:polypeptide(L)
Description:camelid antibody fragment
Chain IDs:B
Chain Length:128
Number of Molecules:1
Biological Source:Camelidae mixed library
Peptide-like Molecules
PRD_900001
Primary Citation
Binding pathway determines norepinephrine selectivity for the human beta 1 AR over beta 2 AR.
Cell Res. 31 569 579 (2021)
PMID: 33093660 DOI: 10.1038/s41422-020-00424-2

Abstact

Beta adrenergic receptors (βARs) mediate physiologic responses to the catecholamines epinephrine and norepinephrine released by the sympathetic nervous system. While the hormone epinephrine binds β1AR and β2AR with similar affinity, the smaller neurotransmitter norepinephrine is approximately tenfold selective for the β1AR. To understand the structural basis for this physiologically important selectivity, we solved the crystal structures of the human β1AR bound to an antagonist carazolol and different agonists including norepinephrine, epinephrine and BI-167107. Structural comparison revealed that the catecholamine-binding pockets are identical between β1AR and β2AR, but the extracellular vestibules have different shapes and electrostatic properties. Metadynamics simulations and mutagenesis studies revealed that these differences influence the path norepinephrine takes to the orthosteric pocket and contribute to the different association rates and thus different affinities.

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