Characterization of the Gene Encoding the Catalytic Subunit of the DNA Polymerase Alpha fromToxoplasma gondii

Abstract

The gene encoding the catalytic subunit of theToxoplasma gondiiDNA polymerase α enzyme has been isolated. The coding region is 6487 bp in length, containing three introns, and specifies a protein of 1690 aa. The seven conserved regions which characterize the polα polypeptide, as well as four of the five polα-specific aa domains, were found in theT. gondiigene. The absence of one of these domains, as well as the presence of a unique cysteine cluster between domains IV and B in theT. gondiipolα, may result in a slight difference in the secondary or even tertiary structure compared with the human homologue and thus may be suitable for designing anti-Toxoplasmadrugs. A number of amino acid differences within the seven conserved regions between the human andT. gondiipolα, as well as variations in the spacings of these regions, were also observed.