Details
| Original language | English |
|---|---|
| Pages (from-to) | 407-416 |
| Number of pages | 10 |
| Journal | Plant physiology and biochemistry |
| Volume | 41 |
| Issue number | 5 |
| Publication status | Published - 23 May 2003 |
Abstract
The preprotein translocase of the outer mitochondrial membrane (also called TOM complex) from A rabidopsis thaliana was characterized by Blue-native gel electrophoresis (BN-PAGE) and Electrospray Tandem Mass Spectrometry (ESI-MS/MS). BN-PAGE allows to prepare a very stable 390 kDa complex that includes six different protein types: the 34 kDa translocation pore TOM40, the 21/23 kDa preprotein receptor TOM20, the small TOM component TOM7 and three further subunits of 10, 6.3 and 6.0 kDa. Primary structures of all TOM subunits were elucidated. The 10 kDa subunit represents a truncated version of the TOM22 preprotein receptor and the two 6 kDa proteins represent subunits possibly homologous to fungal TOM6 and TOM5, although sequence conservation is at the borderline of significance. TOM40, TOM7 and one or both of the 6 kDa subunits form a subcomplex of about 100 kDa. The six TOM proteins from A rabidopsis are encoded by 12 genes, at least 11 of which are expressed. While the subunit composition of the TOM complex from fungi, animals and plants is remarkably conserved, the domain structure of individual TOM proteins differs, e.g. acidic domains in TOM22 and the 6 kDa TOM subunits from Arabidopsis are absent. The domain structure of the Arabidopsis TOM complex does not support the so-called 'acid chain hypothesis', which explains the translocation of proteins across the outer mitochondrial membrane of mitochondria by the binding of preproteins to acidic protein domains within the TOM complex. Functional implications are discussed.
Keywords
- Arabidopsis thaliana, Mitochondria, Protein import apparatus, TOM complex, TOM22
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Physiology
- Biochemistry, Genetics and Molecular Biology(all)
- Genetics
- Agricultural and Biological Sciences(all)
- Plant Science
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In: Plant physiology and biochemistry, Vol. 41, No. 5, 23.05.2003, p. 407-416.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Identification of novel subunits of the TOM complex from Arabidopsis thaliana
AU - Werhahn, Wolf
AU - Jänsch, Lothar
AU - Braun, Hans Peter
N1 - Funding information: We thank Gabi Kühne, Dagmar Lewejohann and Ingrid Robotta for the cultivation of Arabidopsis cell lines and expert technical assistance. Our work was supported by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie.
PY - 2003/5/23
Y1 - 2003/5/23
N2 - The preprotein translocase of the outer mitochondrial membrane (also called TOM complex) from A rabidopsis thaliana was characterized by Blue-native gel electrophoresis (BN-PAGE) and Electrospray Tandem Mass Spectrometry (ESI-MS/MS). BN-PAGE allows to prepare a very stable 390 kDa complex that includes six different protein types: the 34 kDa translocation pore TOM40, the 21/23 kDa preprotein receptor TOM20, the small TOM component TOM7 and three further subunits of 10, 6.3 and 6.0 kDa. Primary structures of all TOM subunits were elucidated. The 10 kDa subunit represents a truncated version of the TOM22 preprotein receptor and the two 6 kDa proteins represent subunits possibly homologous to fungal TOM6 and TOM5, although sequence conservation is at the borderline of significance. TOM40, TOM7 and one or both of the 6 kDa subunits form a subcomplex of about 100 kDa. The six TOM proteins from A rabidopsis are encoded by 12 genes, at least 11 of which are expressed. While the subunit composition of the TOM complex from fungi, animals and plants is remarkably conserved, the domain structure of individual TOM proteins differs, e.g. acidic domains in TOM22 and the 6 kDa TOM subunits from Arabidopsis are absent. The domain structure of the Arabidopsis TOM complex does not support the so-called 'acid chain hypothesis', which explains the translocation of proteins across the outer mitochondrial membrane of mitochondria by the binding of preproteins to acidic protein domains within the TOM complex. Functional implications are discussed.
AB - The preprotein translocase of the outer mitochondrial membrane (also called TOM complex) from A rabidopsis thaliana was characterized by Blue-native gel electrophoresis (BN-PAGE) and Electrospray Tandem Mass Spectrometry (ESI-MS/MS). BN-PAGE allows to prepare a very stable 390 kDa complex that includes six different protein types: the 34 kDa translocation pore TOM40, the 21/23 kDa preprotein receptor TOM20, the small TOM component TOM7 and three further subunits of 10, 6.3 and 6.0 kDa. Primary structures of all TOM subunits were elucidated. The 10 kDa subunit represents a truncated version of the TOM22 preprotein receptor and the two 6 kDa proteins represent subunits possibly homologous to fungal TOM6 and TOM5, although sequence conservation is at the borderline of significance. TOM40, TOM7 and one or both of the 6 kDa subunits form a subcomplex of about 100 kDa. The six TOM proteins from A rabidopsis are encoded by 12 genes, at least 11 of which are expressed. While the subunit composition of the TOM complex from fungi, animals and plants is remarkably conserved, the domain structure of individual TOM proteins differs, e.g. acidic domains in TOM22 and the 6 kDa TOM subunits from Arabidopsis are absent. The domain structure of the Arabidopsis TOM complex does not support the so-called 'acid chain hypothesis', which explains the translocation of proteins across the outer mitochondrial membrane of mitochondria by the binding of preproteins to acidic protein domains within the TOM complex. Functional implications are discussed.
KW - Arabidopsis thaliana
KW - Mitochondria
KW - Protein import apparatus
KW - TOM complex
KW - TOM22
UR - http://www.scopus.com/inward/record.url?scp=0038687177&partnerID=8YFLogxK
U2 - 10.1016/S0981-9428(03)00047-0
DO - 10.1016/S0981-9428(03)00047-0
M3 - Article
AN - SCOPUS:0038687177
VL - 41
SP - 407
EP - 416
JO - Plant physiology and biochemistry
JF - Plant physiology and biochemistry
SN - 0981-9428
IS - 5
ER -