8BEJ

GABA-A receptor a5 homomer - a5V3 - APO

Summary for 8BEJ

• Entry DOI: 10.2210/pdb8bej/pdb
• EMDB information: 16005
• Descriptor: Gamma-aminobutyric acid receptor subunit alpha-5, 2-acetamido-2-deoxy-beta-D-glucopyranose (2 entities in total)
• Functional Keywords: plgic gaba neurotransmission, membrane protein
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 5
• Total formula weight: 206395.59

Authors

Miller, P.S.,Malinauskas, T.M.,Hardwick, S.W.,Chirgadze, D.Y. (deposition date: 2022-10-21, release date: 2023-11-01, Last modification date: 2024-10-16)

Primary citation

Kasaragod, V.B.,Malinauskas, T.,Wahid, A.A.,Lengyel, J.,Knoflach, F.,Hardwick, S.W.,Jones, C.F.,Chen, W.N.,Lucas, X.,El Omari, K.,Chirgadze, D.Y.,Aricescu, A.R.,Cecere, G.,Hernandez, M.C.,Miller, P.S.
The molecular basis of drug selectivity for alpha 5 subunit-containing GABA A receptors.
Nat.Struct.Mol.Biol., 30:1936-1946, 2023

PubMed Abstract: α5 subunit-containing γ-aminobutyric acid type A (GABA) receptors represent a promising drug target for neurological and neuropsychiatric disorders. Altered expression and function contributes to neurodevelopmental disorders such as Dup15q and Angelman syndromes, developmental epilepsy and autism. Effective drug action without side effects is dependent on both α5-subtype selectivity and the strength of the positive or negative allosteric modulation (PAM or NAM). Here we solve structures of drugs bound to the α5 subunit. These define the molecular basis of binding and α5 selectivity of the β-carboline, methyl 6,7-dimethoxy-4-ethyl-β-carboline-3-carboxylate (DMCM), type II benzodiazepine NAMs, and a series of isoxazole NAMs and PAMs. For the isoxazole series, each molecule appears as an 'upper' and 'lower' moiety in the pocket. Structural data and radioligand binding data reveal a positional displacement of the upper moiety containing the isoxazole between the NAMs and PAMs. Using a hybrid molecule we directly measure the functional contribution of the upper moiety to NAM versus PAM activity. Overall, these structures provide a framework by which to understand distinct modulator binding modes and their basis of α5-subtype selectivity, appreciate structure-activity relationships, and empower future structure-based drug design campaigns.

PubMed: 37903907
DOI: 10.1038/s41594-023-01133-1

Experimental method

ELECTRON MICROSCOPY (3.24 Å)