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-Structure paper
Title | Conformational changes in the yeast mitochondrial ABC transporter Atm1 during the transport cycle. |
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Journal, issue, pages | Sci Adv, Vol. 7, Issue 52, Page eabk2392, Year 2021 |
Publish date | Dec 24, 2021 |
Authors | Thomas L Ellinghaus / Thomas Marcellino / Vasundara Srinivasan / Roland Lill / Werner Kühlbrandt / |
PubMed Abstract | The mitochondrial inner membrane ABC transporter Atm1 exports an unknown substrate to the cytosol for iron-sulfur protein biogenesis, cellular iron regulation, and tRNA thio-modification. Mutations ...The mitochondrial inner membrane ABC transporter Atm1 exports an unknown substrate to the cytosol for iron-sulfur protein biogenesis, cellular iron regulation, and tRNA thio-modification. Mutations in the human relative ABCB7 cause the iron storage disease XLSA/A. We determined 3D structures of two complementary states of Atm1 in lipid nanodiscs by electron cryo-microscopy at 2.9- to 3.4-Å resolution. The inward-open structure resembled the known crystal structure of nucleotide-free apo-Atm1 closely. The occluded conformation with bound AMP-PNP-Mg showed a tight association of the two nucleotide-binding domains, a rearrangement of the C-terminal helices, and closure of the putative substrate-binding cavity in the homodimeric transporter. We identified a hydrophobic patch on the C-terminal helices of yeast Atm1, which is unique among type IV ABC transporters of known structure. Truncation mutants of yeast Atm1 suggest that the C-terminal helices stabilize the dimer, yet are not necessary for closure of the nucleotide-binding domains. |
External links | Sci Adv / PubMed:34936443 / PubMed Central |
Methods | EM (single particle) |
Resolution | 2.9 - 7.1 Å |
Structure data | EMDB-13613, PDB-7psl: EMDB-13614, PDB-7psm: EMDB-13615, PDB-7psn: EMDB-13616: EMDB-13617: EMDB-13618: |
Chemicals | ChemComp-LOP: ChemComp-PO4: ChemComp-ANP: ChemComp-MG: |
Source |
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Keywords | TRANSPORT PROTEIN / ABC transporter |