In each pair, the first primer is the 5' sense primer, and second one is the 3' antisense primer. All primers contained a random hexanucleotide sequence (N6) for efficient restriction of the PCR product, followed by restriction sites (underlined): XhoI (CTCGAG), BamHI (GGATCC), NheI (GCTAGC). All sequences are written 5' → 3'. Note that the natural start codons (ATG) of both PfCnA and PfPP7 were removed because translation would originate from the upstream ATG of the pET-15b vector (in order to add the N-terminal His-tag). In PfCnB, the ATG was left intact but the stop codon was removed so that translation could continue into the pET-23a vector to add the C-terminal His-tag.