Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Mapping the agonist binding site of the GABAA receptor: evidence for a beta-strand.
Boileau AJ
,
Evers AR
,
Davis AF
,
Czajkowski C
.
???displayArticle.abstract??? GABAA receptors, along with the receptors for acetylcholine, glycine, and serotonin, are members of a ligand-gated ion channel superfamily (Ortells and Lunt, 1995). Because of the paucity of crystallographic information for these ligand-gated channels, little is known about the structure of their binding sites or how agonist binding is transduced into channel gating. We used the substituted cysteine accessibility method to obtain secondary structural information about the GABA binding site and to systematically identify residues that line its surface. Each residue from alpha1 Y59 to K70 was mutated to cysteine and expressed with wild-type beta2 subunits in Xenopus oocytes or HEK 293 cells. The sulfhydryl-specific reagent N-biotinylaminoethyl methanethiosulfonate (MTSEA-Biotin) was used to covalently modify the cysteine-substituted residues. Receptors with cysteines substituted at positions alpha1 T60, D62, F64, R66, and S68 reacted with MTSEA-Biotin, and alpha1 F64C, R66C, and S68C were protected from reaction by agonist. We conclude that alpha1 F64, R66, and S68 line part of the GABA binding site. The alternating pattern of accessibility of consecutive engineered cysteines to reaction with MTSEA-Biotin indicates that the region from alpha1 Y59 to S68 is a beta-strand.
Akabas,
Identification of acetylcholine receptor channel-lining residues in the entire M2 segment of the alpha subunit.
1994, Pubmed,
Xenbase
Akabas,
Identification of acetylcholine receptor channel-lining residues in the entire M2 segment of the alpha subunit.
1994,
Pubmed
,
Xenbase
Amin,
GABAA receptor needs two homologous domains of the beta-subunit for activation by GABA but not by pentobarbital.
1993,
Pubmed
,
Xenbase
Barnard,
International Union of Pharmacology. XV. Subtypes of gamma-aminobutyric acidA receptors: classification on the basis of subunit structure and receptor function.
1998,
Pubmed
Boileau,
Molecular dissection of benzodiazepine binding and allosteric coupling using chimeric gamma-aminobutyric acidA receptor subunits.
1998,
Pubmed
,
Xenbase
Chen,
Determination of external loop topology in the serotonin transporter by site-directed chemical labeling.
1998,
Pubmed
Cheng,
Relationship between the inhibition constant (K1) and the concentration of inhibitor which causes 50 per cent inhibition (I50) of an enzymatic reaction.
1973,
Pubmed
Cheung,
Identification of cystic fibrosis transmembrane conductance regulator channel-lining residues in and flanking the M6 membrane-spanning segment.
1996,
Pubmed
,
Xenbase
Chou,
Empirical predictions of protein conformation.
1978,
Pubmed
Chou,
Relationships between inhibition constants and fractional inhibition in enzyme-catalyzed reactions with different numbers of reactants, different reaction mechanisms, and different types and mechanisms of inhibition.
1974,
Pubmed
Colquhoun,
Binding, gating, affinity and efficacy: the interpretation of structure-activity relationships for agonists and of the effects of mutating receptors.
1998,
Pubmed
Czajkowski,
Negatively charged amino acid residues in the nicotinic receptor delta subunit that contribute to the binding of acetylcholine.
1993,
Pubmed
,
Xenbase
Davies,
Insensitivity to anaesthetic agents conferred by a class of GABA(A) receptor subunit.
1997,
Pubmed
Egan,
A domain contributing to the ion channel of ATP-gated P2X2 receptors identified by the substituted cysteine accessibility method.
1998,
Pubmed
Graham,
Transformation of rat cells by DNA of human adenovirus 5.
1973,
Pubmed
Javitch,
Mapping the binding-site crevice of the dopamine D2 receptor by the substituted-cysteine accessibility method.
1995,
Pubmed
Javitch,
Mapping the binding-site crevice of the D2 receptor.
1998,
Pubmed
Jones,
Defining affinity with the GABAA receptor.
1998,
Pubmed
Karlin,
Substituted-cysteine accessibility method.
1998,
Pubmed
Kuner,
Structure of the NMDA receptor channel M2 segment inferred from the accessibility of substituted cysteines.
1996,
Pubmed
,
Xenbase
Liman,
Subunit stoichiometry of a mammalian K+ channel determined by construction of multimeric cDNAs.
1992,
Pubmed
,
Xenbase
Nayeem,
Quaternary structure of the native GABAA receptor determined by electron microscopic image analysis.
1994,
Pubmed
Ortells,
Evolutionary history of the ligand-gated ion-channel superfamily of receptors.
1995,
Pubmed
Pérez-García,
Structure of the sodium channel pore revealed by serial cysteine mutagenesis.
1996,
Pubmed
,
Xenbase
Rabow,
From ion currents to genomic analysis: recent advances in GABAA receptor research.
1995,
Pubmed
Robertson,
Potassium currents expressed from Drosophila and mouse eag cDNAs in Xenopus oocytes.
1996,
Pubmed
,
Xenbase
Sieghart,
Structure and pharmacology of gamma-aminobutyric acidA receptor subtypes.
1995,
Pubmed
Sigel,
Point mutations affecting antagonist affinity and agonist dependent gating of GABAA receptor channels.
1992,
Pubmed
,
Xenbase
Smith,
Functional domains of GABAA receptors.
1995,
Pubmed
Smith,
Identification of a [3H]muscimol photoaffinity substrate in the bovine gamma-aminobutyric acidA receptor alpha subunit.
1994,
Pubmed
,
Xenbase
Sun,
Exposure of residues in the cyclic nucleotide-gated channel pore: P region structure and function in gating.
1996,
Pubmed
Widdows,
Modification of the GABA/benzodiazepine receptor with the arginine reagent, 2,3-butanedione.
1987,
Pubmed
Xu,
Identification of channel-lining residues in the M2 membrane-spanning segment of the GABA(A) receptor alpha1 subunit.
1996,
Pubmed
,
Xenbase
