Apicomplexan parasites contain a single lipoic acid synthase located in the plastid - PubMed (original) (raw)

Apicomplexan parasites contain a single lipoic acid synthase located in the plastid

Nadine Thomsen-Zieger et al. FEBS Lett. 2003.

Free article

Abstract

Apicomplexan parasites contain a vestigial plastid called apicoplast which has been suggested to be a site of [Fe-S] cluster biogenesis. Here we report the cloning of lipoic acid synthase (LipA) from Toxoplasma gondii, a well known [Fe-S] protein. It is able to complement a LipA-deficient Escherichia coli strain, clearly demonstrating that the parasite protein is a functional LipA. The N-terminus of T. gondii LipA is unusual with respect to an internal signal peptide preceding an apicoplast targeting domain. Nevertheless, it efficiently targets a reporter protein to the apicoplast of T. gondii whereas co-localization with the fluorescently labeled mitochondrion was not detected. In silico analysis of several apicomplexan genomes indicates that the parasites, in addition to the presumably apicoplast-resident pyruvate dehydrogenase complex, contain three other mitochondrion-localized target proteins for lipoic acid attachment. We also identified single genes for lipoyl (octanoyl)-acyl carrier protein:protein transferase (LipB) and lipoate protein ligase (LplA) in these genomes. It thus appears that unlike plants, which have only two LipA and LipB isoenzymes in both the chloroplasts and the mitochondria, Apicomplexa seem to use the second known lipoylating activity, LplA, for lipoylation in their mitochondrion.

PubMed Disclaimer

Similar articles

Cited by

Publication types

MeSH terms

Substances

LinkOut - more resources