PHYSIOLOGICAL, BIOCHEMICAL AND MOLECULAR ASPECTS OF MITOCHONDRIAL COMPLEX-I IN PLANTS

Respiratory complex I of plant mitochondria has to date been investiga ted with respect to physiological function, biochemical properties and molecular structure. In the respiratory chain complex I is the major entry gate for low potential electrons from matrix NADH, reducing ubiq uinone and utilizing the released energy to pump protons across the in ner membrane. Plant complex I is active against a background of severa l other NAD(P)H dehydrogenases, which do not contribute in proton pump ing, but permit and establish several different routes of shuttling el ectrons from NAD(P)H to ubiquinone, Identification of the correspondin g molecular structures, that is the proteins and genes of the differen t NADH dehydrogenases, will allow more detailed studies of this intera ctive regulatory network in plant mitochondria. Present knowledge of t he structure of complex I and the respective mitochondrial and nuclear genes encoding various subunits of this complex in plants is summariz ed here. (C) 1998 Elsevier Science B.V.