The Environment Shapes the Inner Vestibule of LeuT.
Human neurotransmitter transporters are found in the nervous system terminating synaptic signals by rapid removal of neurotransmitter molecules from the synaptic cleft. The homologous transporter LeuT, found in Aquifex aeolicus, was crystallized in different conformations. Here, we investigated the...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2016-11-01
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| Series: | PLoS Computational Biology |
| Online Access: | https://journals.plos.org/ploscompbiol/article/file?id=10.1371/journal.pcbi.1005197&type=printable |
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| author | Azmat Sohail Kumaresan Jayaraman Santhoshkannan Venkatesan Kamil Gotfryd Markus Daerr Ulrik Gether Claus J Loland Klaus T Wanner Michael Freissmuth Harald H Sitte Walter Sandtner Thomas Stockner |
| author_facet | Azmat Sohail Kumaresan Jayaraman Santhoshkannan Venkatesan Kamil Gotfryd Markus Daerr Ulrik Gether Claus J Loland Klaus T Wanner Michael Freissmuth Harald H Sitte Walter Sandtner Thomas Stockner |
| author_sort | Azmat Sohail |
| collection | DOAJ |
| description | Human neurotransmitter transporters are found in the nervous system terminating synaptic signals by rapid removal of neurotransmitter molecules from the synaptic cleft. The homologous transporter LeuT, found in Aquifex aeolicus, was crystallized in different conformations. Here, we investigated the inward-open state of LeuT. We compared LeuT in membranes and micelles using molecular dynamics simulations and lanthanide-based resonance energy transfer (LRET). Simulations of micelle-solubilized LeuT revealed a stable and widely open inward-facing conformation. However, this conformation was unstable in a membrane environment. The helix dipole and the charged amino acid of the first transmembrane helix (TM1A) partitioned out of the hydrophobic membrane core. Free energy calculations showed that movement of TM1A by 0.30 nm was driven by a free energy difference of ~15 kJ/mol. Distance measurements by LRET showed TM1A movements, consistent with the simulations, confirming a substantially different inward-open conformation in lipid bilayer from that inferred from the crystal structure. |
| format | Article |
| id | doaj-art-df1deda31b4c4be3b4346ef9e659d1d0 |
| institution | Kabale University |
| issn | 1553-734X 1553-7358 |
| language | English |
| publishDate | 2016-11-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Computational Biology |
| spelling | doaj-art-df1deda31b4c4be3b4346ef9e659d1d02025-08-20T03:26:05ZengPublic Library of Science (PLoS)PLoS Computational Biology1553-734X1553-73582016-11-011211e100519710.1371/journal.pcbi.1005197The Environment Shapes the Inner Vestibule of LeuT.Azmat SohailKumaresan JayaramanSanthoshkannan VenkatesanKamil GotfrydMarkus DaerrUlrik GetherClaus J LolandKlaus T WannerMichael FreissmuthHarald H SitteWalter SandtnerThomas StocknerHuman neurotransmitter transporters are found in the nervous system terminating synaptic signals by rapid removal of neurotransmitter molecules from the synaptic cleft. The homologous transporter LeuT, found in Aquifex aeolicus, was crystallized in different conformations. Here, we investigated the inward-open state of LeuT. We compared LeuT in membranes and micelles using molecular dynamics simulations and lanthanide-based resonance energy transfer (LRET). Simulations of micelle-solubilized LeuT revealed a stable and widely open inward-facing conformation. However, this conformation was unstable in a membrane environment. The helix dipole and the charged amino acid of the first transmembrane helix (TM1A) partitioned out of the hydrophobic membrane core. Free energy calculations showed that movement of TM1A by 0.30 nm was driven by a free energy difference of ~15 kJ/mol. Distance measurements by LRET showed TM1A movements, consistent with the simulations, confirming a substantially different inward-open conformation in lipid bilayer from that inferred from the crystal structure.https://journals.plos.org/ploscompbiol/article/file?id=10.1371/journal.pcbi.1005197&type=printable |
| spellingShingle | Azmat Sohail Kumaresan Jayaraman Santhoshkannan Venkatesan Kamil Gotfryd Markus Daerr Ulrik Gether Claus J Loland Klaus T Wanner Michael Freissmuth Harald H Sitte Walter Sandtner Thomas Stockner The Environment Shapes the Inner Vestibule of LeuT. PLoS Computational Biology |
| title | The Environment Shapes the Inner Vestibule of LeuT. |
| title_full | The Environment Shapes the Inner Vestibule of LeuT. |
| title_fullStr | The Environment Shapes the Inner Vestibule of LeuT. |
| title_full_unstemmed | The Environment Shapes the Inner Vestibule of LeuT. |
| title_short | The Environment Shapes the Inner Vestibule of LeuT. |
| title_sort | environment shapes the inner vestibule of leut |
| url | https://journals.plos.org/ploscompbiol/article/file?id=10.1371/journal.pcbi.1005197&type=printable |
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