4BVN

Ultra-thermostable beta1-adrenoceptor with cyanopindolol bound

Summary for 4BVN

• Entry DOI: 10.2210/pdb4bvn/pdb
• Descriptor: BETA-1 ADRENERGIC RECEPTOR, SODIUM ION, Cyanopindolol, ... (6 entities in total)
• Functional Keywords: signaling protein
• Biological source: MELEAGRIS GALLOPAVO (TURKEY)
• Total number of polymer chains: 1
• Total formula weight: 38910.10

Authors

Miller, J.,Nehme, R.,Warne, T.,Edwards, P.C.,Leslie, A.G.W.,Schertler, G.,Tate, C.G. (deposition date: 2013-06-26, release date: 2014-04-02, Last modification date: 2025-07-16)

Primary citation

Miller-Gallacher, J.L.,Nehme, R.,Warne, T.,Edwards, P.C.,Schertler, G.F.X.,Leslie, A.G.W.,Tate, C.G.
The 2.1 A Resolution Structure of Cyanopindolol-Bound Beta1- Adrenoceptor Identifies an Intramembrane Na+ Ion that Stabilises the Ligand-Free Receptor.
Plos One, 9:92727-, 2014

PubMed Abstract: The β1-adrenoceptor (β1AR) is a G protein-coupled receptor (GPCR) that is activated by the endogenous agonists adrenaline and noradrenaline. We have determined the structure of an ultra-thermostable β1AR mutant bound to the weak partial agonist cyanopindolol to 2.1 Å resolution. High-quality crystals (100 μm plates) were grown in lipidic cubic phase without the assistance of a T4 lysozyme or BRIL fusion in cytoplasmic loop 3, which is commonly employed for GPCR crystallisation. An intramembrane Na+ ion was identified co-ordinated to Asp872.50, Ser1283.39 and 3 water molecules, which is part of a more extensive network of water molecules in a cavity formed between transmembrane helices 1, 2, 3, 6 and 7. Remarkably, this water network and Na+ ion is highly conserved between β1AR and the adenosine A2A receptor (rmsd of 0.3 Å), despite an overall rmsd of 2.4 Å for all Cα atoms and only 23% amino acid identity in the transmembrane regions. The affinity of agonist binding and nanobody Nb80 binding to β1AR is unaffected by Na+ ions, but the stability of the receptor is decreased by 7.5°C in the absence of Na+. Mutation of amino acid side chains that are involved in the co-ordination of either Na+ or water molecules in the network decreases the stability of β1AR by 5-10°C. The data suggest that the intramembrane Na+ and associated water network stabilise the ligand-free state of β1AR, but still permits the receptor to form the activated state which involves the collapse of the Na+ binding pocket on agonist binding.

PubMed: 24663151
DOI: 10.1371/JOURNAL.PONE.0092727

Experimental method

X-RAY DIFFRACTION (2.1 Å)