Diversity and origin of alternative NADH : ubiquinone oxidoreductases

Authors
Citation
Sj. Kerscher, Diversity and origin of alternative NADH : ubiquinone oxidoreductases, BBA-BIOENER, 1459(2-3), 2000, pp. 274-283
Citations number
48
Categorie Soggetti
Biochemistry & Biophysics
Journal title
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
ISSN journal
00052728 → ACNP
Volume
1459
Issue
2-3
Year of publication
2000
Pages
274 - 283
Database
ISI
SICI code
0005-2728(20000815)1459:2-3<274:DAOOAN>2.0.ZU;2-#
Abstract
Mitochondria from various organisms, especially plants, fungi and many bact eria contain so-called alternative NADH:ubiquinone oxidoreductases that cat alyse the same redox reaction as respiratory chain complex I, but do not co ntribute to the generation of transmembrane proton gradients. In eucaryotes , these enzymes are associated with the mitochondrial inner membrane, with their NADH reaction site facing either the mitochondrial matrix (internal a lternative NADH:ubiquinone oxidoreductases) or the cytoplasm (external alte rnative NADH:ubiquinone oxidoreductases). Some of these enzymes also accept NADPH as substrate, some require calcium for activity. In the past few yea rs, the characterisation of several alternative NADH:ubiquinone oxidoreduct ases on the DNA and on the protein level, of substrate specificities, mitoc hondrial import and targeting to the mitochondrial inner membrane has great ly improved our understanding of these enzymes. The present review will, wi th an emphasis on yeast model systems, illuminate various aspects of the bi ochemistry of alternative NADH:ubiquinone oxidoreductases, address recent d evelopments and discuss some of the questions still open in the field. (C) 2000 Elsevier Science B.V. All rights reserved.