title: Organisation and expression of small subunit ribosomal RNA genes encoded by a 35-kilobase circular DNA in Plasmodium falciparum.
abstract: A restriction map of the 35-kb circular DNA molecule of Plasmodium falciparum showed that a region of about 6 kb, encoding both a large and a small subunit ribosomal RNA gene, has been duplicated in inverted orientation. The complete sequence of one small subunit rRNA gene is presented as well as an analysis of transcripts from erythrocytic stage parasites. Comparative sequence analysis of the rRNA gene and the proposed secondary structure of the rRNA suggest that it is of organellar origin. Intriguingly, while some characteristics of the small subunit rRNA gene are similar to mitochondrial sequences, others are more like those of plastids. The origin of the circular DNA molecule and evolutionary implications of its genetic content are discussed.
authors.affiliation: Division of Parasitology, National Institute for Medical Research, Mill Hill, London, U.K.
authors.forename: M J
authors.initials: MJ
authors.lastname: Gardner
authors.forename: J E
authors.initials: JE
authors.lastname: Feagin
authors.forename: D J
authors.initials: DJ
authors.lastname: Moore
authors.forename: D F
authors.initials: DF
authors.lastname: Spencer
authors.forename: M W
authors.initials: MW
authors.lastname: Gray
authors.forename: D H
authors.initials: DH
authors.lastname: Williamson
authors.forename: R J
authors.initials: RJ
authors.lastname: Wilson
mesh_terms: D000818:Animals; D001483:Base Sequence; D004270:DNA, Circular / Q000235:genetics; D016054:DNA, Protozoan / Q000235:genetics*; D015870:Gene Expression; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010963:Plasmodium falciparum / Q000235:genetics*; D016053:RNA, Protozoan / Q000737:chemistry / Q000235:genetics*; D012335:RNA, Ribosomal / Q000737:chemistry / Q000235:genetics*; D015183:Restriction Mapping
chemical_list: D004270:DNA, Circular; D016054:DNA, Protozoan; D016053:RNA, Protozoan; D012335:RNA, Ribosomal