THE GENE ENCODING DNA POLYMERASE-ALPHA FROM PLASMODIUM-FALCIPARUM

The gene encoding DNA polymerase alpha from the human malaria parasite Plasmodium falciparum has been sequenced and characterised. The deduc ed amino acid sequence possesses the seven sequence motifs which chara cterise eukaryotic replicative DNA polymerases (I-VII) and four of fiv e motifs (A-E) identified in a DNA polymerases. The predicted protein also contains sequences which are reminiscent of Plasmodium proteins b ut absent from other DNA polymerases. These include four blocks of add itional amino acids interspersed with the conserved motifs of the DNA polymerases, four asparagine rich sequences and a novel carboxy-termin al extension. Repetitive sequences similar to those found in other mal arial proteins are also present. cDNA-directed PCR was used to establi sh the presence of these features in the approximately 7kb mRNA. The c oding sequence contains a single intron. The gene for DNAPolalpha is l ocated on chromosome 4 and is transcribed in both asexual and sexual e rythrocytic stages of the parasite.