The Molecular Mechanism of Transport by the Mitochondrial ADP/ATP Carrier.

TitleThe Molecular Mechanism of Transport by the Mitochondrial ADP/ATP Carrier.
Publication TypeJournal Article
Year of Publication2019
AuthorsRuprecht, JJ, King, MS, Zögg, T, Aleksandrova, AA, Pardon, E, Crichton, PG, Steyaert, J, Kunji, ERS
JournalCell
Volume176
Issue3
Pagination435-447.e15
Date Published2019 Jan 24
ISSN1097-4172
Abstract

Mitochondrial ADP/ATP carriers transport ADP into the mitochondrial matrix for ATP synthesis, and ATP out to fuel the cell, by cycling between cytoplasmic-open and matrix-open states. The structure of the cytoplasmic-open state is known, but it has proved difficult to understand the transport mechanism in the absence of a structure in the matrix-open state. Here, we describe the structure of the matrix-open state locked by bongkrekic acid bound in the ADP/ATP-binding site at the bottom of the central cavity. The cytoplasmic side of the carrier is closed by conserved hydrophobic residues, and a salt bridge network, braced by tyrosines. Glycine and small amino acid residues allow close-packing of helices on the matrix side. Uniquely, the carrier switches between states by rotation of its three domains about a fulcrum provided by the substrate-binding site. Because these features are highly conserved, this mechanism is likely to apply to the whole mitochondrial carrier family. VIDEO ABSTRACT.

DOI10.1016/j.cell.2018.11.025
Alternate JournalCell
Citation Key10.1016/j.cell.2018.11.025
PubMed ID30611538
PubMed Central IDPMC6349463