Housekeeping and other metabolic functions of the Plasmodium plastid

Abstract

The malaria parasite carries a plastid called the apicoplast that has been the subject of intense study in the last 15 years. Having originated from red-algal plastids, the apicoplast has lost its ability to photosynthesize, but carries out other essential functions such as type-II fatty acid synthesis, biosynthesis of haem and isoprenoid synthesis; the DOXP pathway for isoprenoid synthesis has recently been demonstrated to be the only pathway critical for parasite survival in the erythrocytic stage. The apicoplast also has a functional Suf system for assembly of (Fe–S) complexes on target proteins. The organelle has a 35 kb, double-stranded DNA genome that encodes a set of RNAs and proteins, the latter being translated from organellar mRNA by an active translation machinery, a major component of which is encoded by the nucleus. This article reviews current knowledge of housekeeping functions of the Plasmodium apicoplast and its (Fe–S) assembly system and discusses these components as sites for drug intervention against malaria.