7PQX

Structure of CtAtm1 in the inward-facing open conformation

Summary for 7PQX

• Entry DOI: 10.2210/pdb7pqx/pdb
• EMDB information: 13606
• Descriptor: Putative iron-sulfur protein (1 entity in total)
• Functional Keywords: abc exporter, membrane protein
• Biological source: Thermochaetoides thermophila DSM 1495
• Total number of polymer chains: 2
• Total formula weight: 154401.61

Authors

Li, P.,Wang, K.T.,Gourdon, P.E. (deposition date: 2021-09-20, release date: 2022-08-10, Last modification date: 2024-07-17)

Primary citation

Li, P.,Hendricks, A.L.,Wang, Y.,Villones, R.L.E.,Lindkvist-Petersson, K.,Meloni, G.,Cowan, J.A.,Wang, K.,Gourdon, P.
Structures of Atm1 provide insight into [2Fe-2S] cluster export from mitochondria.
Nat Commun, 13:4339-4339, 2022

PubMed Abstract: In eukaryotes, iron-sulfur clusters are essential cofactors for numerous physiological processes, but these clusters are primarily biosynthesized in mitochondria. Previous studies suggest mitochondrial ABCB7-type exporters are involved in maturation of cytosolic iron-sulfur proteins. However, the molecular mechanism for how the ABCB7-type exporters participate in this process remains elusive. Here, we report a series of cryo-electron microscopy structures of a eukaryotic homolog of human ABCB7, CtAtm1, determined at average resolutions ranging from 2.8 to 3.2 Å, complemented by functional characterization and molecular docking in silico. We propose that CtAtm1 accepts delivery from glutathione-complexed iron-sulfur clusters. A partially occluded state links cargo-binding to residues at the mitochondrial matrix interface that line a positively charged cavity, while the binding region becomes internalized and is partially divided in an early occluded state. Collectively, our findings substantially increase the understanding of the transport mechanism of eukaryotic ABCB7-type proteins.

PubMed: 35896548
DOI: 10.1038/s41467-022-32006-8

Experimental method

ELECTRON MICROSCOPY (3.08 Å)