Mitochondrial protein import. Requirement of presequence elements and tom components for precursor binding to the TOM complex.
Protein translocation across the outer mitochondrial membrane is mediated by the translocator called the TOM (translocase of the outer mitochondrial membrane) complex. The TOM complex possesses two presequence binding sites on the cytosolic side (the cis site) and on the intermembrane space side (the trans site). Here we analyzed the requirement of presequence elements and subunits of the TOM complex for presequence binding to the cis and trans sites of the TOM complex. The N-terminal 14 residues of the presequence of subunit 9 of F(0)-ATPase are required for binding to the trans site. The interaction between the presequence and the cis site is not sufficient to anchor the precursor protein to the TOM complex. Tom7 constitutes or is close to the trans site and has overlapping functions with the C-terminal intermembrane space domain of Tom22 in the mitochondrial protein import.
Esaki
Masatoshi
M
Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Japan.
Shimizu
Hidaka
H
Ono
Tomoko
T
Yamamoto
Hayashi
H
Kanamori
Takashi
T
Nishikawa
Shuh-Ichi
S
Endo
Toshiya
T
D008565:Membrane Proteins / Q000502:physiology; D026901:Membrane Transport Proteins / Q000502:physiology; D008727:Methotrexate / Q000494:pharmacology; D033681:Mitochondrial Membrane Transport Proteins / Q000502:physiology; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism*; D021381:Protein Transport; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology
D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins; D011498:Protein Precursors; D029701:Saccharomyces cerevisiae Proteins; C090857:TOM22 protein, S cerevisiae; C106794:TOM5 protein, S cerevisiae; C082532:TOM6 protein, S cerevisiae; C099634:TOM7 protein, S cerevisiae; D008727:Methotrexate