Structural highlights
Function
[TOM71_YEAST] Involved in MBF1-mediated mitochondrial morphogenesis.[1] [HSP71_YEAST] May play a role in the transport of polypeptides both across the mitochondrial membranes and into the endoplasmic reticulum. A functional difference between SSA1 and SSA2 proteins is expected. SSA1 can participate in the ATP-dependent disassembly of clathrin-coated vesicles.[2]
Publication Abstract from PubMed
Mitochondrial precursors are transported through the translocase of the outer membrane (TOM) complex. Tom70/Tom71 is a major surface receptor of the TOM complex for mitochondrial precursors and facilitates Hsp70/Hsp90-escorted precursor translocation into the mitochondrion. Previous structural studies of Tom71 have revealed that it contains an N-terminal and a C-terminal domain and that the two domains may remain in an open conformation when binding to Hsp70/Hsp90. In a newly obtained crystal form of a complex of Tom71 and the Hsp70 C-terminus, the N-terminal domain was found to have rotated about 12 degrees towards the C-terminal domain compared with the previous determined crystal structure of Tom71 in the open conformation. This newly solved structure is defined as the ;intermediate conformation'. The domain rearrangements in Tom71 significantly change the surface hydrophobicity and the volume of the precursor-binding pocket. This work suggests that Tom70/Tom71-family members may exhibit structural plasticity from the intermediate conformation to the fully open conformation when complexed with Hsp70/Hsp90. This structural plasticity enables the precursor receptors to accommodate different precursor substrates for mitochondrial translocation.
The structural plasticity of Tom71 for mitochondrial precursor translocations.,Li J, Cui W, Sha B Acta Crystallogr Sect F Struct Biol Cryst Commun. 2010 Sep 1;66(Pt, 9):985-9. Epub 2010 Aug 21. PMID:20823510[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kondo-Okamoto N, Shaw JM, Okamoto K. Tetratricopeptide repeat proteins Tom70 and Tom71 mediate yeast mitochondrial morphogenesis. EMBO Rep. 2008 Jan;9(1):63-9. Epub 2007 Nov 16. PMID:18007655 doi:http://dx.doi.org/10.1038/sj.embor.7401113
- ↑ Li XS, Reddy MS, Baev D, Edgerton M. Candida albicans Ssa1/2p is the cell envelope binding protein for human salivary histatin 5. J Biol Chem. 2003 Aug 1;278(31):28553-61. Epub 2003 May 21. PMID:12761219 doi:http://dx.doi.org/10.1074/jbc.M300680200
- ↑ Li J, Cui W, Sha B. The structural plasticity of Tom71 for mitochondrial precursor translocations. Acta Crystallogr Sect F Struct Biol Cryst Commun. 2010 Sep 1;66(Pt, 9):985-9. Epub 2010 Aug 21. PMID:20823510 doi:10.1107/S1744309110025522
