Identification of a Novel Gene NDF6 Which Is Essential for the Accumulation of Chloroplastic NAD(P)H Dehydrogenase

Abstract

Chloroplastic NAD(P)H dehydrogenase (NDH) genes were identified as a homologous gene cluster of a respiratory enzyme, complex I, when the whole chloroplast genome sequence was determined. So far, 14 ndh genes were identified in higher plants. While 11 of ndh genes are coded in chloroplastic genome and the others are in nuclear genome, no electron-accepter subunits have been identified yet. The comparison with eukaryotic complex I, which consists of more than 40 subunits, suggests that several missing subunits exist in chloroplastic NDH. Our recent approach using in silico screening method based on co-expression analysis has predicted several missing subunits of NDH. In this report, we characterized a novel gene NDF6 which is essential for NDH accumulation.