TY - JOUR
T1 - Cryo-EM structure of GABA transporter 1 reveals substrate recognition and transport mechanism
AU - Nayak, Smruti Ranjan
AU - Joseph, Deepthi
AU - Höfner, Georg
AU - Dakua, Archishman
AU - Athreya, Arunabh
AU - Wanner, Klaus T.
AU - Kanner, Baruch I.
AU - Penmatsa, Aravind
N1 - Publisher Copyright:
© 2023, The Author(s).
PY - 2023/7
Y1 - 2023/7
N2 - The inhibitory neurotransmitter γ-aminobutyric acid (GABA) is cleared from the synaptic cleft by the sodium- and chloride-coupled GABA transporter GAT1. Inhibition of GAT1 prolongs the GABAergic signaling at the synapse and is a strategy to treat certain forms of epilepsy. In this study, we present the cryo-electron microscopy structure of Rattus norvegicus GABA transporter 1 (rGAT1) at a resolution of 3.1 Å. The structure elucidation was facilitated by epitope transfer of a fragment-antigen binding (Fab) interaction site from the Drosophila dopamine transporter (dDAT) to rGAT1. The structure reveals rGAT1 in a cytosol-facing conformation, with a linear density in the primary binding site that accommodates a molecule of GABA, a displaced ion density proximal to Na site 1 and a bound chloride ion. A unique insertion in TM10 aids the formation of a compact, closed extracellular gate. Besides yielding mechanistic insights into ion and substrate recognition, our study will enable the rational design of specific antiepileptics.
AB - The inhibitory neurotransmitter γ-aminobutyric acid (GABA) is cleared from the synaptic cleft by the sodium- and chloride-coupled GABA transporter GAT1. Inhibition of GAT1 prolongs the GABAergic signaling at the synapse and is a strategy to treat certain forms of epilepsy. In this study, we present the cryo-electron microscopy structure of Rattus norvegicus GABA transporter 1 (rGAT1) at a resolution of 3.1 Å. The structure elucidation was facilitated by epitope transfer of a fragment-antigen binding (Fab) interaction site from the Drosophila dopamine transporter (dDAT) to rGAT1. The structure reveals rGAT1 in a cytosol-facing conformation, with a linear density in the primary binding site that accommodates a molecule of GABA, a displaced ion density proximal to Na site 1 and a bound chloride ion. A unique insertion in TM10 aids the formation of a compact, closed extracellular gate. Besides yielding mechanistic insights into ion and substrate recognition, our study will enable the rational design of specific antiepileptics.
UR - http://www.scopus.com/inward/record.url?scp=85163743450&partnerID=8YFLogxK
U2 - 10.1038/s41594-023-01011-w
DO - 10.1038/s41594-023-01011-w
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C2 - 37400654
AN - SCOPUS:85163743450
SN - 1545-9993
VL - 30
SP - 1023
EP - 1032
JO - Nature Structural and Molecular Biology
JF - Nature Structural and Molecular Biology
IS - 7
ER -