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Molecular nanoenvironment of the mitochondrial presequence translocase
Author(s) -
Mehnert Carola S.,
Gebert Michael,
Oeljeklaus Silke,
Pfanner Nikolaus,
Laan Martin
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.585.1
Subject(s) - translocase , translocase of the outer membrane , translocase of the inner membrane , mitochondrial carrier , atp–adp translocase , inner mitochondrial membrane , inner membrane , mitochondrion , chemistry , membrane protein , biochemistry , membrane transport protein , oxidative phosphorylation , intermembrane space , respiratory chain , biology , microbiology and biotechnology , biophysics , mitochondrial membrane transport protein , bacterial outer membrane , membrane , chromosomal translocation , gene , escherichia coli
The model that membrane proteins form large, highly organized networks instead of floating freely in the lipid bilayer, is just beginning to develop. In an environment as protein rich as the inner mitochondrial membrane, one has to analyze the whole protein network in order to fully understand fundamental mechanisms like protein translocation and oxidative phosphorylation. Molecular machines like the presequence translocase of the inner mitochondrial membrane (TIM23) are a central part of these networks. Analysis of its interactions with high affinity chromatography followed by mass spectrometry gave first impressions of the complex components of the network, but lacked quantitative information. A strategy to obtain this information, firstly focusing on TIM23, was to calibrate the analysis of isolated complexes with defined amounts of in vitro synthesized proteins. The protein clusters found comprised the respiratory chain complexes, metabolite carriers, dehydrogenases and the constituents of TIM23. Interesting new stoichiometric interactors were the ADP/ATP carrier AAC2 and the protein Mgr2, which appears to be a new core component of the translocase.