Carbonic anhydrase subunits of the mitochondrial NADH dehydrogenase complex (complex I) in plants

authored by
Hans Peter Braun, Eduardo Zabaleta
Abstract

The mitochondrial nicotinamide adenine dinucleotide, reduced (NADH) dehydrogenase complex (complex I) of plants has a molecular mass of about 1000 kDa and is composed of more than 40 distinct protein subunits. About three quarter of these subunits are homologous to complex I subunits of heterotrophic eukaryotes, whereas the remaining subunits are unique to plants. Among them are three to five structurally related proteins that resemble an archaebacterial γ-type carbonic anhydrase (γCA). The γCA subunits are attached to the membrane arm of complex I on the matrix-exposed side and form an extra spherical domain. At the same time, they span the inner mitochondrial membrane and are essential for assembly of the protein complex. Expression of the genes encoding γCA subunits is reduced if plants are cultivated in the presence of elevated CO2 concentration. The functional role of these subunits within plant mitochondria is currently unknown but might be related to photorespiration. We propose that the complex I-integrated γCAs are involved in mitochondrial HCO3- formation to allow efficient recycling of inorganic carbon for CO2 fixation in chloroplasts under high light conditions.

Organisation(s)
Institute of Plant Genetics
External Organisation(s)
Universidad Nacional de Mar del Plata
Type
Article
Journal
Physiologia plantarum
Volume
129
Pages
114-122
No. of pages
9
ISSN
0031-9317
Publication date
18.09.2006
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Physiology, Genetics, Plant Science, Cell Biology
Electronic version(s)
https://doi.org/10.15488/11666 (Access: Open)
https://doi.org/10.1111/j.1399-3054.2006.00773.x (Access: Unknown)
https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1399-3054.2006.00773.x (Access: Unknown)