Coupling chemical energy by the hsp70/tim44 complex to drive protein translocation into mitochondrial

被引:8
作者
Cyr, DM
机构
[1] Department of Cell Biology, School of Medicine, University of Alabama at Birmingham, Birmingham
关键词
mitochondrial biogenesis; protein translocation; hsp70; DnaJ proteins; molecular chaperones;
D O I
10.1023/A:1022455621111
中图分类号
Q6 [生物物理学];
学科分类号
071011 ;
摘要
A dynamic complex between the mitochondrial cognate of hsp70 (mthsp70) and the inner membrane protein tim44 couples energy derived from ATP hydrolysis to drive multiple steps in the mitochondrial protein import pathway: (1) The Delta Psi dependent import step and the mthsp70/tim44 complex cooperate to facilitate the unidirectional transfer of the mitochondrial targeting signal across the inner membrane. (2) The mthsp70/tim44 complex helps to unfold domains on precursors proteins that arrive at the import apparatus in a folded conformation on the cis side of the outer membrane. (3) Completion of import is then driven by the mthsp70/tim44 complex in a manner that is independent of Delta Psi. Mechanisms proposed to explain how the mthsp70/tim44 complex harvests chemical energy to drive these aspects of the import process are discussed.
引用
收藏
页码:29 / 34
页数:6
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