| Structural highlights
Function
[TOM5_YEAST] Component of the TOM (translocase of outer membrane) receptor complex responsible for the recognition and translocation of cytosolically synthesized mitochondrial preproteins. TOM5 is involved in insertion of preproteins into the TOM40 translocation pore.[1] [TOM40_YEAST] Channel-forming protein essential for import of protein precursors into mitochondria.[2] [TOM22_YEAST] Central component of the TOM (translocase of outer membrane) receptor complex responsible for the recognition and translocation of cytosolically synthesized mitochondrial preproteins. Together with TOM20 and TOM70 functions as the transit peptide receptor at the surface of the mitochondrion outer membrane and facilitates the movement of preproteins into the TOM40 translocation pore. Docks TOM20 and TOM70 for interaction with the general TOM40 import pore (GIP) complex. May regulate the TOM machinery organization, stability and channel gating.[3] [4] [5] [TOM7_YEAST] Component of the TOM (translocase of outer membrane) receptor complex responsible for the recognition and translocation of cytosolically synthesized mitochondrial preproteins. TOM7 is involved in assembly and stability of the TOM complex.[6] [TOM6_YEAST] Component of the TOM (translocase of outer membrane) receptor complex responsible for the recognition and translocation of cytosolically synthesized mitochondrial preproteins. TOM6 is involved in assembly and stability of the TOM complex.[7]
Publication Abstract from PubMed
The translocase of the outer mitochondrial membrane (TOM) is the main entry gate for proteins(1-4). Here we use cryo-electron microscopy to report the structure of the yeast TOM core complex(5-9) at 3.8 A resolution. The structure reveals the high-resolution architecture of the translocator consisting of two Tom40 beta-barrel channels and alpha-helical transmembrane subunits, providing insight into critical features conserved in all eukaryotes(1-3). Each Tom40 beta-barrel is surrounded by small Tom subunits, and tethered by two Tom22 and one phospholipid. The N-terminal extension of Tom40 forms a helix inside the channel; mutational analysis reveals its dual role in early and late steps in biogenesis of intermembrane-space proteins in cooperation with Tom5. Each Tom40 channel possesses two precursor exit sites: Tom22, Tom40 and Tom7 guide presequence-containing preproteins to the exit in the midst of the dimer, whereas Tom5 and the Tom40 N-extension guide presequence-less preproteins to the exit at the dimer periphery.
Structure of the mitochondrial import gate reveals distinct preprotein paths.,Araiso Y, Tsutsumi A, Qiu J, Imai K, Shiota T, Song J, Lindau C, Wenz LS, Sakaue H, Yunoki K, Kawano S, Suzuki J, Wischnewski M, Schutze C, Ariyama H, Ando T, Becker T, Lithgow T, Wiedemann N, Pfanner N, Kikkawa M, Endo T Nature. 2019 Oct 10. pii: 10.1038/s41586-019-1680-7. doi:, 10.1038/s41586-019-1680-7. PMID:31600774[8]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Dietmeier K, Honlinger A, Bomer U, Dekker PJ, Eckerskorn C, Lottspeich F, Kubrich M, Pfanner N. Tom5 functionally links mitochondrial preprotein receptors to the general import pore. Nature. 1997 Jul 10;388(6638):195-200. doi: 10.1038/40663. PMID:9217162 doi:http://dx.doi.org/10.1038/40663
- ↑ Rapaport D, Neupert W. Biogenesis of Tom40, core component of the TOM complex of mitochondria. J Cell Biol. 1999 Jul 26;146(2):321-31. doi: 10.1083/jcb.146.2.321. PMID:10427088 doi:http://dx.doi.org/10.1083/jcb.146.2.321
- ↑ van Wilpe S, Ryan MT, Hill K, Maarse AC, Meisinger C, Brix J, Dekker PJ, Moczko M, Wagner R, Meijer M, Guiard B, Honlinger A, Pfanner N. Tom22 is a multifunctional organizer of the mitochondrial preprotein translocase. Nature. 1999 Sep 30;401(6752):485-9. PMID:10519552 doi:http://dx.doi.org/10.1038/46802
- ↑ Model K, Meisinger C, Prinz T, Wiedemann N, Truscott KN, Pfanner N, Ryan MT. Multistep assembly of the protein import channel of the mitochondrial outer membrane. Nat Struct Biol. 2001 Apr;8(4):361-70. doi: 10.1038/86253. PMID:11276259 doi:http://dx.doi.org/10.1038/86253
- ↑ Honlinger A, Kubrich M, Moczko M, Gartner F, Mallet L, Bussereau F, Eckerskorn C, Lottspeich F, Dietmeier K, Jacquet M, et al.. The mitochondrial receptor complex: Mom22 is essential for cell viability and directly interacts with preproteins. Mol Cell Biol. 1995 Jun;15(6):3382-9. PMID:7760834
- ↑ Model K, Meisinger C, Prinz T, Wiedemann N, Truscott KN, Pfanner N, Ryan MT. Multistep assembly of the protein import channel of the mitochondrial outer membrane. Nat Struct Biol. 2001 Apr;8(4):361-70. doi: 10.1038/86253. PMID:11276259 doi:http://dx.doi.org/10.1038/86253
- ↑ Model K, Meisinger C, Prinz T, Wiedemann N, Truscott KN, Pfanner N, Ryan MT. Multistep assembly of the protein import channel of the mitochondrial outer membrane. Nat Struct Biol. 2001 Apr;8(4):361-70. doi: 10.1038/86253. PMID:11276259 doi:http://dx.doi.org/10.1038/86253
- ↑ Araiso Y, Tsutsumi A, Qiu J, Imai K, Shiota T, Song J, Lindau C, Wenz LS, Sakaue H, Yunoki K, Kawano S, Suzuki J, Wischnewski M, Schutze C, Ariyama H, Ando T, Becker T, Lithgow T, Wiedemann N, Pfanner N, Kikkawa M, Endo T. Structure of the mitochondrial import gate reveals distinct preprotein paths. Nature. 2019 Oct 10. pii: 10.1038/s41586-019-1680-7. doi:, 10.1038/s41586-019-1680-7. PMID:31600774 doi:http://dx.doi.org/10.1038/s41586-019-1680-7
|
