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 deduced amino acid sequence possesses the seven sequence motifs which characterise eukaryotic replicative DNA polymerases (I-VII) and four of five motifs (A-E) identified in alpha DNA polymerases. The predicted protein also contains sequences which are reminiscent of Plasmodium proteins but absent from other DNA polymerases. These include four blocks of additional amino acids interspersed with the conserved motifs of the DNA polymerases, four asparagine rich sequences and a novel carboxy-terminal extension. Repetitive sequences similar to those found in other malarial proteins are also present. cDNA-directed PCR was used to establish the presence of these features in the approximately 7kb mRNA. The coding sequence contains a single intron. The gene for DNAPol alpha is located on chromosome 4 and is transcribed in both asexual and sexual erythrocytic stages of the parasite.