Crystal Structure of the ORP8 Lipid Transport ORD Domain: Model of Lipid Transport
ORPs are lipid-transport proteins belonging to the oxysterol-binding protein family. They facilitate the transfer of lipids between different intracellular membranes, such as the ER and plasma membrane. We have solved the crystal structure of the ORP8 lipid transport domain (ORD8). The ORD8 exhibite...
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MDPI AG
2023-07-01
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| Online Access: | https://www.mdpi.com/2073-4409/12/15/1974 |
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| author | Andrea Eisenreichova Martin Klima Midhun Mohan Anila Alena Koukalova Jana Humpolickova Bartosz Różycki Evzen Boura |
| author_facet | Andrea Eisenreichova Martin Klima Midhun Mohan Anila Alena Koukalova Jana Humpolickova Bartosz Różycki Evzen Boura |
| author_sort | Andrea Eisenreichova |
| collection | DOAJ |
| description | ORPs are lipid-transport proteins belonging to the oxysterol-binding protein family. They facilitate the transfer of lipids between different intracellular membranes, such as the ER and plasma membrane. We have solved the crystal structure of the ORP8 lipid transport domain (ORD8). The ORD8 exhibited a β-barrel fold composed of anti-parallel β-strands, with three α-helices replacing β-strands on one side. This mixed alpha–beta structure was consistent with previously solved structures of ORP2 and ORP3. A large cavity (≈1860 Å<sup>3</sup>) within the barrel was identified as the lipid-binding site. Although we were not able to obtain a lipid-bound structure, we used computer simulations based on our crystal structure to dock PS and PI4P molecules into the putative lipid-binding site of the ORD8. Comparative experiments between the short ORD8<sup>ΔLid</sup> (used for crystallography) and the full-length ORD8 (lid containing) revealed the lid’s importance for stable lipid binding. Fluorescence assays revealed different transport efficiencies for PS and PI4P, with the lid slowing down transport and stabilizing cargo. Coarse-grained simulations highlighted surface-exposed regions and hydrophobic interactions facilitating lipid bilayer insertion. These findings enhance our comprehension of ORD8, its structure, and lipid transport mechanisms, as well as provide a structural basis for the design of potential inhibitors. |
| first_indexed | 2024-03-11T00:29:40Z |
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| issn | 2073-4409 |
| language | English |
| last_indexed | 2024-03-11T00:29:40Z |
| publishDate | 2023-07-01 |
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| series | Cells |
| spelling | doaj.art-aa5771591daf43dd99f152b57f039c372023-11-18T22:45:09ZengMDPI AGCells2073-44092023-07-011215197410.3390/cells12151974Crystal Structure of the ORP8 Lipid Transport ORD Domain: Model of Lipid TransportAndrea Eisenreichova0Martin Klima1Midhun Mohan Anila2Alena Koukalova3Jana Humpolickova4Bartosz Różycki5Evzen Boura6Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nam. 2., 166 10 Prague, Czech RepublicInstitute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nam. 2., 166 10 Prague, Czech RepublicInstitute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, PolandInstitute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nam. 2., 166 10 Prague, Czech RepublicInstitute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nam. 2., 166 10 Prague, Czech RepublicInstitute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, PolandInstitute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nam. 2., 166 10 Prague, Czech RepublicORPs are lipid-transport proteins belonging to the oxysterol-binding protein family. They facilitate the transfer of lipids between different intracellular membranes, such as the ER and plasma membrane. We have solved the crystal structure of the ORP8 lipid transport domain (ORD8). The ORD8 exhibited a β-barrel fold composed of anti-parallel β-strands, with three α-helices replacing β-strands on one side. This mixed alpha–beta structure was consistent with previously solved structures of ORP2 and ORP3. A large cavity (≈1860 Å<sup>3</sup>) within the barrel was identified as the lipid-binding site. Although we were not able to obtain a lipid-bound structure, we used computer simulations based on our crystal structure to dock PS and PI4P molecules into the putative lipid-binding site of the ORD8. Comparative experiments between the short ORD8<sup>ΔLid</sup> (used for crystallography) and the full-length ORD8 (lid containing) revealed the lid’s importance for stable lipid binding. Fluorescence assays revealed different transport efficiencies for PS and PI4P, with the lid slowing down transport and stabilizing cargo. Coarse-grained simulations highlighted surface-exposed regions and hydrophobic interactions facilitating lipid bilayer insertion. These findings enhance our comprehension of ORD8, its structure, and lipid transport mechanisms, as well as provide a structural basis for the design of potential inhibitors.https://www.mdpi.com/2073-4409/12/15/1974lipid transportORDORP8PSPI4Pplasma membrane |
| spellingShingle | Andrea Eisenreichova Martin Klima Midhun Mohan Anila Alena Koukalova Jana Humpolickova Bartosz Różycki Evzen Boura Crystal Structure of the ORP8 Lipid Transport ORD Domain: Model of Lipid Transport Cells lipid transport ORD ORP8 PS PI4P plasma membrane |
| title | Crystal Structure of the ORP8 Lipid Transport ORD Domain: Model of Lipid Transport |
| title_full | Crystal Structure of the ORP8 Lipid Transport ORD Domain: Model of Lipid Transport |
| title_fullStr | Crystal Structure of the ORP8 Lipid Transport ORD Domain: Model of Lipid Transport |
| title_full_unstemmed | Crystal Structure of the ORP8 Lipid Transport ORD Domain: Model of Lipid Transport |
| title_short | Crystal Structure of the ORP8 Lipid Transport ORD Domain: Model of Lipid Transport |
| title_sort | crystal structure of the orp8 lipid transport ord domain model of lipid transport |
| topic | lipid transport ORD ORP8 PS PI4P plasma membrane |
| url | https://www.mdpi.com/2073-4409/12/15/1974 |
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