4US4
Crystal Structure of the Bacterial NSS Member MhsT in an Occluded Inward-Facing State (lipidic cubic phase form)
Summary for 4US4
| Entry DOI | 10.2210/pdb4us4/pdb |
| Related | 4US3 |
| Descriptor | TRANSPORTER, TRYPTOPHAN, SODIUM ION, ... (6 entities in total) |
| Functional Keywords | transport protein, neurotransmitter, neurotransmitter sodium symporter family, leut fold, amino acid transporter, secondary transporter, membrane protein |
| Biological source | BACILLUS HALODURANS |
| Total number of polymer chains | 1 |
| Total formula weight | 49554.43 |
| Authors | Malinauskaite, L.,Quick, M.,Reinhard, L.,Lyons, J.A.,Yano, H.,Javitch, J.A.,Nissen, P. (deposition date: 2014-07-02, release date: 2014-09-24, Last modification date: 2024-01-10) |
| Primary citation | Malinauskaite, L.,Quick, M.,Reinhard, L.,Lyons, J.A.,Yano, H.,Javitch, J.A.,Nissen, P. A Mechanism for Intracellular Release of Na+ by Neurotransmitter/Sodium Symporters Nat.Struct.Mol.Biol., 21:1006-, 2014 Cited by PubMed Abstract: Neurotransmitter/sodium symporters (NSSs) terminate synaptic signal transmission by Na+-dependent reuptake of released neurotransmitters. Key conformational states have been reported for the bacterial homolog LeuT and an inhibitor-bound Drosophila dopamine transporter. However, a coherent mechanism of Na+-driven transport has not been described. Here, we present two crystal structures of MhsT, an NSS member from Bacillus halodurans, in occluded inward-facing states with bound Na+ ions and L-tryptophan, providing insight into the cytoplasmic release of Na+. The switch from outward- to inward-oriented states is centered on the partial unwinding of transmembrane helix 5, facilitated by a conserved GlyX9Pro motif that opens an intracellular pathway for water to access the Na2 site. We propose a mechanism, based on our structural and functional findings, in which solvation through the TM5 pathway facilitates Na+ release from Na2 and the transition to an inward-open state. PubMed: 25282149DOI: 10.1038/NSMB.2894 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.6 Å) |
Structure validation
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