Details
| Original language | English |
|---|---|
| Pages (from-to) | 18936-18942 |
| Number of pages | 7 |
| Journal | Journal of Biological Chemistry |
| Volume | 268 |
| Issue number | 25 |
| Publication status | Published - 1993 |
| Externally published | Yes |
Abstract
In potato, cytochrome c reductase, a protein complex of the respiratory chain, exhibits processing activity toward mitochondrial precursor proteins. One of the two cooperating components of the processing peptidase was shown to be identical with subunit III of the complex. Here we report that two additional proteins of the complex (subunit I and II) share 40-50% sequence identity with the processing enhancing protein, the other component of the processing enzyme from fungi and mammals. Thus the composition and structure of the complex integrated processing peptidase seems to be different from its fungal and mammalian counterparts. Cytochrome c reductase from potato is extraordinarily stable, and separation of subunit III from the complex leads to aggregation of the remaining subcomplex and irreversible loss of processing activity. Expression of the three high molecular weight subunits of the complex allowed purification of each individual protein. Neither the individual subunits nor their combinations are active in in vitro processing assays suggesting that they may need the structural support of the complex for activity. In contrast to mitochondrial processing peptidases from other organisms, the purified potato enzyme is active in the presence of high salt (above 1 M NaCl) and works efficiently without addition of metal ions. These data indicate that potato cytochrome c reductase is a bifunctional protein complex with unique features. Possibly, there is a more general evolutionary relationship between cytochrome c reductases and mitochondrial processing peptidases than hitherto assumed.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Biochemistry
- Biochemistry, Genetics and Molecular Biology(all)
- Molecular Biology
- Biochemistry, Genetics and Molecular Biology(all)
- Cell Biology
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In: Journal of Biological Chemistry, Vol. 268, No. 25, 1993, p. 18936-18942.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Characterization of the bifunctional cytochrome c reductase-processing peptidase complex from potato mitochondria
AU - Emmermann, Michael
AU - Braun, Hans-Peter
AU - Arretz, M.
AU - Schmitz, Udo
PY - 1993
Y1 - 1993
N2 - In potato, cytochrome c reductase, a protein complex of the respiratory chain, exhibits processing activity toward mitochondrial precursor proteins. One of the two cooperating components of the processing peptidase was shown to be identical with subunit III of the complex. Here we report that two additional proteins of the complex (subunit I and II) share 40-50% sequence identity with the processing enhancing protein, the other component of the processing enzyme from fungi and mammals. Thus the composition and structure of the complex integrated processing peptidase seems to be different from its fungal and mammalian counterparts. Cytochrome c reductase from potato is extraordinarily stable, and separation of subunit III from the complex leads to aggregation of the remaining subcomplex and irreversible loss of processing activity. Expression of the three high molecular weight subunits of the complex allowed purification of each individual protein. Neither the individual subunits nor their combinations are active in in vitro processing assays suggesting that they may need the structural support of the complex for activity. In contrast to mitochondrial processing peptidases from other organisms, the purified potato enzyme is active in the presence of high salt (above 1 M NaCl) and works efficiently without addition of metal ions. These data indicate that potato cytochrome c reductase is a bifunctional protein complex with unique features. Possibly, there is a more general evolutionary relationship between cytochrome c reductases and mitochondrial processing peptidases than hitherto assumed.
AB - In potato, cytochrome c reductase, a protein complex of the respiratory chain, exhibits processing activity toward mitochondrial precursor proteins. One of the two cooperating components of the processing peptidase was shown to be identical with subunit III of the complex. Here we report that two additional proteins of the complex (subunit I and II) share 40-50% sequence identity with the processing enhancing protein, the other component of the processing enzyme from fungi and mammals. Thus the composition and structure of the complex integrated processing peptidase seems to be different from its fungal and mammalian counterparts. Cytochrome c reductase from potato is extraordinarily stable, and separation of subunit III from the complex leads to aggregation of the remaining subcomplex and irreversible loss of processing activity. Expression of the three high molecular weight subunits of the complex allowed purification of each individual protein. Neither the individual subunits nor their combinations are active in in vitro processing assays suggesting that they may need the structural support of the complex for activity. In contrast to mitochondrial processing peptidases from other organisms, the purified potato enzyme is active in the presence of high salt (above 1 M NaCl) and works efficiently without addition of metal ions. These data indicate that potato cytochrome c reductase is a bifunctional protein complex with unique features. Possibly, there is a more general evolutionary relationship between cytochrome c reductases and mitochondrial processing peptidases than hitherto assumed.
UR - http://www.scopus.com/inward/record.url?scp=0027225845&partnerID=8YFLogxK
U2 - 10.15488/11696
DO - 10.15488/11696
M3 - Article
C2 - 8360183
AN - SCOPUS:0027225845
VL - 268
SP - 18936
EP - 18942
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 25
ER -