Plasmodium falciparum: properties of an alpha-like DNA polymerase, the key enzyme in DNA synthesis.
An alpha-like DNA polymerase has been identified and characterized in the extracts from the malarial parasite Plasmodium falciparum. The enzyme is sensitive to the specific inhibitors of alpha-DNA polymerase, N-ethylmaleimide and aphidicolin, and is cell-cycle specific. High activity has been found in the schizont, is lower in trophozoites, and has only negligible activity in the ring form. The enzyme has a molecular weight of about Mr 100,000-103,000 estimated by detecting activity in SDS-polyacrylamide electrophoresis and by Bio-Gel filtration. Another active band of a molecular Mr 68,000 was detected by SDS electrophoresis when the enzyme was stored for 2 months at -20 degrees C. The catalytic activity of parasite enzyme was optimal between pH 8 and pH 9. The apparent Michaelis constant for dTTP was 4.3 microM.
Abu-Elheiga
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Department of Parasitology, Kuvin Centre for the Study of Tropical and Infectious Diseases, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Spira
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DT
Bachrach
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D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D016590:Aphidicolin; D002453:Cell Cycle; D002850:Chromatography, Gel; D004247:DNA / Q000096:biosynthesis*; D004257:DNA Polymerase II / Q000032:analysis* / Q000037:antagonists & inhibitors / Q000276:immunology; D004224:Diterpenes / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D005033:Ethylmaleimide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D010963:Plasmodium falciparum / Q000201:enzymology* / Q000235:genetics
D000911:Antibodies, Monoclonal; D004224:Diterpenes; D016590:Aphidicolin; D004247:DNA; D004257:DNA Polymerase II; D005033:Ethylmaleimide