title: Molecular characterisation of the enolase gene from the human malaria parasite Plasmodium falciparum. Evidence for ancestry within a photosynthetic lineage.
abstract: We have isolated and characterised the gene encoding the glycolytic enzyme enolase (2-phospho-D-glycerate hydrolase) from the human malaria parasite Plasmodium falciparum. This was achieved using a combination of cDNA sequencing and inverse-PCR techniques. The gene maps to chromosome 10 of the parasite. We have also mapped two further glycolytic enzyme genes, glyceraldehyde-3-phosphate dehydrogenase and triose-phosphate isomerase, to chromosome 14. The enolase gene encodes a protein of 446 amino acids (48.7 kDa), and all amino acid residues implicated in substrate/cofactor binding and catalysis are conserved in the malarial enolase molecule. The predicted protein sequence displays approximately 60-70% identity to enolase molecules of other eukaryotes, the closest relationship with its homologues seen amongst the seven fully described glycolytic pathway enzymes of P. falciparum. Of particular significance in this well conserved molecule is a characteristic 5-amino-acid insertion sequence that is identical in position and virtually identical in primary structure to that which is otherwise found uniquely in plant enolase proteins. This pentapeptide, together with other features of the plasmodial sequence, points to a common ancestry with photosynthetic organisms at the level of a protein-encoding nuclear gene, thus extending earlier analyses of nuclear small-subunit ribosomal RNA genes, and of an extrachromosomal circular 35-kb DNA element found in P. falciparum, which have also indicated such a relationship.
authors.affiliation: Department of Biochemistry and Applied Molecular Biology, University of Manchester Institute of Science and Technology, England.
authors.forename: M
authors.initials: M
authors.lastname: Read
authors.forename: K E
authors.initials: KE
authors.lastname: Hicks
authors.forename: P F
authors.initials: PF
authors.lastname: Sims
authors.forename: J E
authors.initials: JE
authors.lastname: Hyde
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000201:enzymology / Q000235:genetics; D001483:Base Sequence; D005075:Biological Evolution; D002874:Chromosome Mapping; D017124:Conserved Sequence; D017931:DNA Primers; D004251:DNA Transposable Elements; D018076:DNA, Complementary / Q000032:analysis; D016054:DNA, Protozoan / Q000235:genetics / Q000302:isolation & purification; D015870:Gene Expression; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics; D006019:Glycolysis / Q000235:genetics; D006801:Humans; D008288:Malaria / Q000469:parasitology; D008969:Molecular Sequence Data; D010751:Phosphopyruvate Hydratase / Q000235:genetics*; D010788:Photosynthesis / Q000235:genetics*; D010944:Plants / Q000201:enzymology / Q000235:genetics; D010963:Plasmodium falciparum / Q000201:enzymology* / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D014305:Triose-Phosphate Isomerase / Q000235:genetics
chemical_list: D017931:DNA Primers; D004251:DNA Transposable Elements; D018076:DNA, Complementary; D016054:DNA, Protozoan; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D010751:Phosphopyruvate Hydratase; D014305:Triose-Phosphate Isomerase