The Arabidopsis mitochondrial proteome project (1996-2004)

More recent data can be found at

An Arabidopsis thaliana mitochondrial proteome project was started for a comprehensive investigation of mitochondrial functions in plants. As a first step the proteome of mitochondria isolated from suspension cell cultures was characterized by high resolution 2D gel electrophoresis and mass spectrometry. Currently the proteomes of selected Arabidopsis knock-out mutants concerning nuclear genes of mitochondrial proteins are under investigation in our laboratory.
Wolf Werhahn and Hans-Peter Braun

Characterization of outer mitochondrial membrane proteins from Arabidopsis thaliana

Two-dimensional resolution of outer mitochondrial membrane proteins from Arabidopsis thaliana by Blue-native / Tricine SDS polyacrylamide gel electrophoresis (Werhahn et al. 2001, Plant Physiol. 125, 943-954, Werhahn et al. 2003, Plant Pysiol. Biochem. 41, 407-416). One dominant protein complex forms part of the outer mitochondrial membrane: "the preprotein translocase of the outer mitochondrial membrane", also called the "TOM complex". In Arabidopsis the TOM complex consists of 6 subunits of 34 kDa (TOM40), 23/21 kDa (TOM20), 10 kDa (TOM22 or TOM9), 8 kDa (TOM7), 6.3 kDa (TOM6) and 6.0 kDa (TOM5). There are four different genes encoding TOM20 in Arabidopsis, two genes encoding TOM40, TOM22 and TOM7 and single-copy genes encoding TOM6 and TOM5.

See also a 2D gel of the TOM complex from Solanum tuberosum (potato)


List of identified proteins
(last update: Jan. 2003)

Proteins were identified by Edman Degradation (ED) or mass spectrometry (ESI-MS/MS, [MS]).
Protein No Identity Accession Identification Sequences determined
1 TOM40     (34.1 kDa) At3g20000 ED ADLLPPLTAAQVDAK
2 TOM20-2  (23.0 kDa) At1g27390 ED KXPELHMQFMNQG...
3 TOM20-3  (22.6 kDa) At3g27080 ED KHNFDLATQFFQQAVD...
4 TOM20-4  (21.0 kDa) At5g40930 ED KASQFFQLAVEEQPES...
5 TOM9-2    (10.2 kDa) At5g43970 ED, MS EAQINEIELQQASLLGA...
6 TOM7-1    ( 8.3 kDa) At5g41685 ED KVNKGKGKGSKGASS...
7 TOM6       ( 6.3 kDa) At1g49410 ED MFPGMFMRKPXK
8 TOM5       ( 6.0 kDa) At5g08040 ED VNNVVSIEKMXA