Reference : Impact of mutations affecting ND mitochondria-encoded Subunits on the activity and assem...
Scientific journals : Article
Life sciences : Biochemistry, biophysics & molecular biology
http://hdl.handle.net/2268/35251
Impact of mutations affecting ND mitochondria-encoded Subunits on the activity and assembly of complex I in chlamydomonas. Implication for the structural organization of the enzyme
English
Cardol, Pierre mailto [Université de Liège - ULg > Département des sciences de la vie > Biochimie végétale >]
Matagne, René-Fernand mailto [Université de Liège - ULg > Services généraux (Faculté des sciences) > Relations académiques et scientifiques (Sciences) >]
Remacle, Claire mailto [Université de Liège - ULg > Département des sciences de la vie > Génétique >]
21-Jun-2002
Journal of Molecular Biology
Academic Press Ltd Elsevier Science Ltd
319
5
1211-1221
Yes (verified by ORBi)
International
0022-2836
London
[en] complex I assembly ; chlamydomonas mitochondrial mutants ; ND subunits ; NADH dehydrogenase ; NADH ; ubiquinone oxidoreductase
[en] The mitochondrial rotenone-sensitive NADH:ubiquinone oxidoreductase (complex 1) comprises more than 35 subunits, the majority of which are encoded by the nucleus. In Chlamydomonas reinhardtii, only five components (ND1, ND2, ND4, ND5 and ND6) are coded for by the mitochondrial genome. Here, we characterize two mitochondrial mutants (dum5 and dum17) showing strong reduction or inactivation of complex I activity: dum5 is a IT deletion in the 3' UTR of nd5 whereas dum17 is a IT deletion in the coding sequence of nd6. The impact of these mutations and of mutations affecting nd1, nd4 and nd4/nd5 genes on the assembly of complex I is investigated. After separation of the respiratory complexes by blue native (BN)-PAGE or sucrose gradient centrifugation, we demonstrate that the absence of intact ND1 or ND6 subunit prevents the assembly of the 850 kDa whole complex, whereas the loss of ND4 or ND4/ND5 leads to the formation of a subcomplex of 650 kDa present in reduced amount. The implications of our findings for the possible role of these ND subunits on the activity of complex I and for the structural organization of the membrane arm of the enzyme are discussed. In mitochondria from all the strains analyzed, we moreover detected a 160210 kDa fragment comprising the hydrophilic 49 kDa and 76 kDa subunits of the complex I peripheral arm and showing NADH dehydrogenase activity. (C) 2002 Elsevier Science Ltd. All rights reserved.
http://hdl.handle.net/2268/35251
10.1016/S0022-2836(02)00407-2

File(s) associated to this reference

Fulltext file(s):

FileCommentaryVersionSizeAccess
Restricted access
Cardol et al 2002Ulg.pdfAuthor postprint939.27 kBRequest copy

Bookmark and Share SFX Query

All documents in ORBi are protected by a user license.