COMPLETE GENE MAP OF THE PLASTID-LIKE DNA OF THE MALARIA PARASITE PLASMODIUM-FALCIPARUM

Malaria parasites, and other parasitic protists of the Phylum Apicompl exa, carry a plastid-like genome with greatly reduced sequence complex ity. This 35 kb DNA circle resembles the plastid DNA of non-photosynth etic plants, encoding almost exclusively components involved in gene e xpression. The complete gene map described here includes genes for dup licated large and small subunit rRNAs, 25 species of tRNA, three subun its of a eubacterial RNA polymerase, 17 ribosomal proteins, and a tran slation elongation factor. In addition, it codes for an unusual member of the Clp family of chaperones, as well as an open reading frame of unknown function found in red algal plastids. Transcription is polycis tronic. This plastid-like DNA molecule is conserved in several genera of apicomplexans and is conjectured to have been acquired by an early progenitor of the Phylum by secondary endosymbiosis. The function of t he organelle (plastid) carrying this DNA remains obscure, but appears to be specified by genes transferred to the nucleus. (C) 1996 Academic Press Limited