A novel connection between nucleotide and carbohydrate metabolism in mitochondria: sugar regulation of the Arabidopsis nucleoside diphosphate kinase 3a gene.

Sugar metabolism is intricately connected with mitochondria through the conversion of sugars to ATP, and through the production of carbon skeletons that can be used in anabolic processes. Sugar molecules also take part in signalling cascades. In this study we investigated the impact of sucrose on the expression of the Arabidopsis thaliana Nucleoside Diphosphate Kinase gene family (NDPK, EC 2.

The pea mitochondrial nucleoside diphosphate kinase cleaves DNA and RNA.

Here, we present the characterization of a plant NDPK exhibiting nuclease activity. This is the first identification of a nuclease localised in the intermembrane space of plant mitochondria. The recombinant pea NDPK3 protein cleaves not only supercoiled plasmid DNA, but also highly structured RNA molecules such as tRNAs or the 3'UTR of the atp9 mRNA suggesting that the NDPK3 nuclease activity has a structural requirement.