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-Structure paper
Title | Cryo-EM structure of the mitochondrial protein-import channel TOM complex at near-atomic resolution. |
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Journal, issue, pages | Nat Struct Mol Biol, Vol. 26, Issue 12, Page 1158-1166, Year 2019 |
Publish date | Nov 18, 2019 |
Authors | Kyle Tucker / Eunyong Park / |
PubMed Abstract | Nearly all mitochondrial proteins are encoded by the nuclear genome and imported into mitochondria after synthesis on cytosolic ribosomes. These precursor proteins are translocated into mitochondria ...Nearly all mitochondrial proteins are encoded by the nuclear genome and imported into mitochondria after synthesis on cytosolic ribosomes. These precursor proteins are translocated into mitochondria by the TOM complex, a protein-conducting channel in the mitochondrial outer membrane. We have determined high-resolution cryo-EM structures of the core TOM complex from Saccharomyces cerevisiae in dimeric and tetrameric forms. Dimeric TOM consists of two copies each of five proteins arranged in two-fold symmetry: pore-forming β-barrel protein Tom40 and four auxiliary α-helical transmembrane proteins. The pore of each Tom40 has an overall negatively charged inner surface attributed to multiple functionally important acidic patches. The tetrameric complex is essentially a dimer of dimeric TOM, which may be capable of forming higher-order oligomers. Our study reveals the detailed molecular organization of the TOM complex and provides new insights about the mechanism of protein translocation into mitochondria. |
External links | Nat Struct Mol Biol / PubMed:31740857 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.06 - 4.1 Å |
Structure data | EMDB-20728, PDB-6ucu: EMDB-20729, PDB-6ucv: |
Chemicals | ChemComp-LMT: ChemComp-MC3: |
Source |
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Keywords | TRANSLOCASE / Membrane protein / mitochondrial protein import / mitochondrial outer membrane / protein translocation |