3LCA

Structure of Tom71 complexed with Hsp70 Ssa1 C terminal tail indicating conformational plasticity

Summary for 3LCA

• Entry DOI: 10.2210/pdb3lca/pdb
• Descriptor: Protein TOM71, Heat shock protein SSA1, GLYCEROL, ... (4 entities in total)
• Functional Keywords: chaperone, conformational plasticity, membrane, mitochondrion, mitochondrion outer membrane, tpr repeat, transmembrane, transport protein
• Biological source: Saccharomyces cerevisiae (yeast); More
• Cellular location: Mitochondrion outer membrane ; Single- pass membrane protein : P38825; Cytoplasm : P10591
• Total number of polymer chains: 2
• Total formula weight: 61613.27

Authors

Li, J.Z.,Sha, B.D. (deposition date: 2010-01-10, release date: 2010-12-22, Last modification date: 2023-09-06)

Primary citation

Li, J.,Cui, W.,Sha, B.
The structural plasticity of Tom71 for mitochondrial precursor translocations.
Acta Crystallogr.,Sect.F, 66:985-989, 2010

PubMed Abstract: 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.

PubMed: 20823510
DOI: 10.1107/S1744309110025522

Experimental method

X-RAY DIFFRACTION (2.19 Å)