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The NADH-binding subunit of respiratory chain complex I is nuclear-encoded in plants and identified only in mitochondria

Grohmann, Lutz; Rasmusson, Allan G. LU ; Heiser, Volker; Thieck, Oliver and Brennicke, Axel (1996) In Plant Journal 10(5). p.793-803
Abstract

In higher plants, genes for subunits of respiratory chain complex I (NADH:ubiquinone oxidoreductase) have so far been identified solely in organellar genomes. At least nine subunits are encoded by the mitochondrial DNA and 11 homologues by the plastid DNA. One of the 'key' components of complex I is the subunit binding the substrate NADH. The corresponding gene for the mitochondrial subunit has now been cloned and identified in the nuclear genome from potato (Solanum tuberosum). The mature protein consists of 457 amino acids and is preceded by a mitochondrial targeting sequence of 30 amino acids. The protein is evolutionarily related to the NADH-binding subunits of complex I from other eukaryotes and is well conserved in the structural... (More)

In higher plants, genes for subunits of respiratory chain complex I (NADH:ubiquinone oxidoreductase) have so far been identified solely in organellar genomes. At least nine subunits are encoded by the mitochondrial DNA and 11 homologues by the plastid DNA. One of the 'key' components of complex I is the subunit binding the substrate NADH. The corresponding gene for the mitochondrial subunit has now been cloned and identified in the nuclear genome from potato (Solanum tuberosum). The mature protein consists of 457 amino acids and is preceded by a mitochondrial targeting sequence of 30 amino acids. The protein is evolutionarily related to the NADH-binding subunits of complex I from other eukaryotes and is well conserved in the structural domains predicted for binding the substrate NADH, the FMN and one iron-sulphur cluster. Expression examined in different potato tissues by Northern blot analysis shows the highest steady-state mRNA levels in flowers. Precursor proteins translated in vitro from the cDNA are imported into isolated potato mitochondria in a Δψ-dependent manner. The processed translation product has an apparent molecular mass of 55 kDa, identical to the mature protein present in the purified plant mitochondrial complex I. However, the in-vitro translated protein is not imported into isolated chloroplasts. To further investigate whether the complex I-like enzyme in chloroplasts contains an analogous subunit for binding of NAD(P)H, different plastid protein fractions were tested with a polyclonal antiserum directed against the bovine 51 kDa NADH-binding subunit. In none of the different thylakoid or stroma protein fractions analysed were specific cross-reactive polypeptides detected. These results are discussed particularly with respect to the structure of a potential complex I in chloroplasts and the nature of its acceptor site.

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author
publishing date
type
Contribution to journal
publication status
published
subject
in
Plant Journal
volume
10
issue
5
pages
11 pages
publisher
Wiley-Blackwell
external identifiers
  • Scopus:0030295294
ISSN
0960-7412
DOI
10.1046/j.1365-313X.1996.10050793.x
language
English
LU publication?
no
id
83c60efe-cc33-4505-974d-26df330dcb74
date added to LUP
2016-05-31 21:31:46
date last changed
2016-10-13 05:09:36
@misc{83c60efe-cc33-4505-974d-26df330dcb74,
  abstract     = {<p>In higher plants, genes for subunits of respiratory chain complex I (NADH:ubiquinone oxidoreductase) have so far been identified solely in organellar genomes. At least nine subunits are encoded by the mitochondrial DNA and 11 homologues by the plastid DNA. One of the 'key' components of complex I is the subunit binding the substrate NADH. The corresponding gene for the mitochondrial subunit has now been cloned and identified in the nuclear genome from potato (Solanum tuberosum). The mature protein consists of 457 amino acids and is preceded by a mitochondrial targeting sequence of 30 amino acids. The protein is evolutionarily related to the NADH-binding subunits of complex I from other eukaryotes and is well conserved in the structural domains predicted for binding the substrate NADH, the FMN and one iron-sulphur cluster. Expression examined in different potato tissues by Northern blot analysis shows the highest steady-state mRNA levels in flowers. Precursor proteins translated in vitro from the cDNA are imported into isolated potato mitochondria in a Δψ-dependent manner. The processed translation product has an apparent molecular mass of 55 kDa, identical to the mature protein present in the purified plant mitochondrial complex I. However, the in-vitro translated protein is not imported into isolated chloroplasts. To further investigate whether the complex I-like enzyme in chloroplasts contains an analogous subunit for binding of NAD(P)H, different plastid protein fractions were tested with a polyclonal antiserum directed against the bovine 51 kDa NADH-binding subunit. In none of the different thylakoid or stroma protein fractions analysed were specific cross-reactive polypeptides detected. These results are discussed particularly with respect to the structure of a potential complex I in chloroplasts and the nature of its acceptor site.</p>},
  author       = {Grohmann, Lutz and Rasmusson, Allan G. and Heiser, Volker and Thieck, Oliver and Brennicke, Axel},
  issn         = {0960-7412},
  language     = {eng},
  number       = {5},
  pages        = {793--803},
  publisher    = {ARRAY(0xc350a60)},
  series       = {Plant Journal},
  title        = {The NADH-binding subunit of respiratory chain complex I is nuclear-encoded in plants and identified only in mitochondria},
  url          = {http://dx.doi.org/10.1046/j.1365-313X.1996.10050793.x},
  volume       = {10},
  year         = {1996},
}