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Background: Emergence of drug-resistant Plasmodium falciparum has created an urgent need for new drug targets. DNA polymerase δ is an essential enzyme required for chromosomal DNA replication and repair, and therefore may be a potential target for anti-malarial drug development. However, little is known of the characteristics and function of this P. falciparum enzyme. Methods: The coding sequences of DNA polymerase δ catalytic subunit (PfPolδ-cat), DNA polymerase δ small subunit (PfPolδS) and proliferating cell nuclear antigen (PfPCNA) from chloroquine- and pyrimethamine-resistant P. falciparum strain K1% were amplified, cloned into an expression vector and expressed in Escherichia coli. The recombinant proteins were analysed by SDS-PAGE and identified by LC-MS/MS. PfPolδ-cat was biochemically characterized. The roles of PfPolδS and PfPCNA in PfPolδ-cat function were investigated. In addition, inhibitory effects of 1%1% compounds were tested on PfPolδ-cat activity and on in vitro parasite growth using SYBR Green I assay. Results: The purified recombinant protein PfPolδ-cat, PfPolδS and PfPCNA showed on SDS-PAGE the expected size of 1%4%3%, 5%7% and 3%4% kDa, respectively. Predicted amino acid sequence of the PfPolδ-cat and PfPolδS had 5%9%.2% and 2%4%.7% % similarity respectively to that of the human counterpart. The PfPolδ-cat possessed both DNA polymerase and 3%'-5%' exonuclease activities. It used both Mg2%+ and Mn2%+ as cofactors and was inhibited by high KCl salt (>2%0%0% mM). PfPolδS stimulated PfPolδ-cat activity threefolds and up to fourfolds when PfPCNA was included in the assay. Only two compounds were potent inhibitors of PfPolδ-cat, namely, butylphenyl-dGTP (BuPdGTP; IC5%0% of 3%8% μM) and 7%-acetoxypentyl-( 3%, 4% dichlorobenzyl) guanine (7%-acetoxypentyl-DCBG; IC5%0% of 5%5% μM). The latter compound showed higher inhibition on parasite growth (IC5%0% of 4%.1% μM). Conclusions: Recombinant PfPolδ-cat, PfPolδS and PfPCNA were successfully expressed and purified. PfPolS and PfPCNA increased DNA polymerase activity of PfPolδ-cat. The high sensitivity of PfPolδ to BuPdGTP can be used to differentiate parasite enzyme from mammalian and human counterparts. Interestingly, 7%-acetoxypentyl-DCBG showed inhibitory effects on both enzyme activity and parasite growth. Thus, 7%-acetoxypentyl-DCBG is a potential candidate for future development of a new class of anti-malarial agents targeting parasite replicative DNA polymerase. [ABSTRACT FROM AUTHOR]