7awn

Structure of the thermostabilized EAAT1 cryst mutant in complex with rubidium and barium and the allosteric inhibitor UCPH101

spinqualitylabelsall models 7awn, resolution 3.92Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7awn is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.92Å Ligands: 6Z6, BA, RB Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Disease EAA1_HUMAN Alternating hemiplegia of childhood;Episodic ataxia type 6. The disease is caused by mutations affecting the gene represented in this entry. Function AAAT_HUMAN Sodium-dependent amino acids transporter that has a broad substrate specificity, with a preference for zwitterionic amino acids. It accepts as substrates all neutral amino acids, including glutamine, asparagine, and branched-chain and aromatic amino acids, and excludes methylated, anionic, and cationic amino acids (PubMed:8702519). Through binding of the fusogenic protein syncytin-1/ERVW-1 may mediate trophoblasts syncytialization, the spontaneous fusion of their plasma membranes, an essential process in placental development (PubMed:10708449, PubMed:23492904). (Microbial infection) Acts as a cell surface receptor for Feline endogenous virus RD114. (Microbial infection) Acts as a cell surface receptor for Baboon M7 endogenous virus. (Microbial infection) Acts as a cell surface receptor for type D simian retroviruses. EAA1_HUMAN Transports L-glutamate and also L- and D-aspartate. Essential for terminating the postsynaptic action of glutamate by rapidly removing released glutamate from the synaptic cleft. Acts as a symport by cotransporting sodium. Publication Abstract from PubMed Excitatory amino acid transporters (EAATs) maintain glutamate gradients in the brain essential for neurotransmission and to prevent neuronal death. They use ionic gradients as energy source and co-transport transmitter into the cytoplasm with Na(+) and H(+) , while counter-transporting K(+) to re-initiate the transport cycle. However, the molecular mechanisms underlying ion-coupled transport remain incompletely understood. Here, we present 3D X-ray crystallographic and cryo-EM structures, as well as thermodynamic analysis of human EAAT1 in different ion bound conformations, including elusive counter-transport ion bound states. Binding energies of Na(+) and H(+) , and unexpectedly Ca(2+) , are coupled to neurotransmitter binding. Ca(2+) competes for a conserved Na(+) site, suggesting a regulatory role for Ca(2+) in glutamate transport at the synapse, while H(+) binds to a conserved glutamate residue stabilizing substrate occlusion. The counter-transported ion binding site overlaps with that of glutamate, revealing the K(+) -based mechanism to exclude the transmitter during the transport cycle and to prevent its neurotoxic release on the extracellular side. The ion-coupling mechanism of human excitatory amino acid transporters.,Canul-Tec JC, Kumar A, Dhenin J, Assal R, Legrand P, Rey M, Chamot-Rooke J, Reyes N EMBO J. 2021 Nov 8:e108341. doi: 10.15252/embj.2021108341. PMID:34747040 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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