The 29.9 kDa subunit of mitochondrial complex I is involved in the enzyme active/de-active transitions

• Type: Article in International Scientific Journal
• Date: 2005

Authors

ushakova, av (Author) Other; duarte, m (Author) ICBAS; vinogradov, ad (Author) Other; videira, a (Author) ICBAS

Journal

Title: Journal of Molecular Biology

Vol. 351

Pages: 327-333

ISSN: 0022-2836

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 8 Citations

Scopus - 8 Citations

Other information

Authenticus ID: P-000-1Y3

DOI: 10.1016/j.jmb.2005.06.006

Abstract (EN): Mitochondrial respiratory chain complex I undergoes transitions from active to de-activated forms. We have investigated the phenomenon in submitochondrial particles from Neurospora crassa wild-type and a null-mutant lacking the 29.9 kDa. nuclear-coded subunit of complex I. Based on enzymatic activities, genetic crosses and analysis of mitochondrial proteins in sucrose gradients, we found that about one-fifth of complex I with catalytic properties similar to the wild-type enzyme is assembled in the mutant. Mutant complex I still displays active/de-active transitions, indicating that other proteins are involved in the phenomenon. However, the kinetic characteristics of complex I active/de-active transitions in nuo29.9 differ from wild-type. The spontaneous de-activation of the mutant enzyme is much slower, implicating the 29.9 kDa. polypeptide in this event. We suggest that the fungal 29.9 kDa. protein and its homologues in other organisms may modulate the active/de-active transitions of complex I. (c) 2005 Elsevier Ltd. All rights reserved.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7