Identification and molecular characterisation of DNA damaging agent induced expression of Plasmodium falciparum recombination protein PfRad51.

Rad51 protein, the eukaryotic homologue of Escherichia coli RecA protein plays a pivotal role in recombinational repair mechanism. We have identified a new homologue of Rad51 from the apicomplexan parasite Plasmodium falciparum, designated PfRad51. The PfRad51 gene codes for a 351 amino acid polypeptide with a predicted molecular mass of 38720, and shares 66-75% sequence identity within the catalytic region with Rad51 from human, yeast and other protozoan parasites such as Trypanosoma and Leishmania. The expression of PfRad51 transcript as well as protein in the intra-erythrocytic in vitro culture of P. flalciparum was found to be up-regulated in response to the DNA damaging agent methyl methanesulfonate, suggesting its functional involvement in recombinational repair process. PfRad51 is the first apicomplexan gene identified that codes for a recombination protein, and it offers an excellent model for studying DNA damage inducible gene expression in such parasites.