7PSM

S. cerevisiae Atm1 in MSP1D1 nanodiscs with bound AMP-PNP and Mg2+

Summary for 7PSM

• Entry DOI: 10.2210/pdb7psm/pdb
• EMDB information: 13614
• Descriptor: Iron-sulfur clusters transporter ATM1, mitochondrial, PHOSPHOAMINOPHOSPHONIC ACID-ADENYLATE ESTER, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: abc transporter, transport protein
• Biological source: Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
• Total number of polymer chains: 2
• Total formula weight: 139170.72

Authors

Ellinghaus, T.L.,Kuehlbrandt, W. (deposition date: 2021-09-23, release date: 2021-12-29, Last modification date: 2024-07-17)

Primary citation

Ellinghaus, T.L.,Marcellino, T.,Srinivasan, V.,Lill, R.,Kuhlbrandt, W.
Conformational changes in the yeast mitochondrial ABC transporter Atm1 during the transport cycle.
Sci Adv, 7:eabk2392-eabk2392, 2021

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 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.

PubMed: 34936443
DOI: 10.1126/sciadv.abk2392

Experimental method

ELECTRON MICROSCOPY (3.4 Å)