Identification of an Arabidopsis cDNA encoding a lipoyltransferase locatedin plastids

In plant cells. the pyruvate dehydrogenase (PDH) complex that requires lipo ic acid as an essential coenzyme is located in plastids and mitochondria. T he enzyme complex has to be lipoylated in both organelles. However, the lip oyltransferase located in plastids has not been reported. In this study, an Arabidopsis thaliana LIP2p cDNA for a lipoyltransferase located in plastid s has been identified. We have shown that this cDNA encodes a lipoyltransfe rase by demonstrating its ability to complement an Escherichia coli mutant lacking lipoyltransferase activity, and that LIP2p is targeted into chlorop lasts. These findings suggest that LIP2p is located in plastids and respons ible for lipoylation of the plastidial PDH complex. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All righ ts reserved.