Scheme of PCR experiments. The alignment shows the three amplicons, which led to the ORF and untranslated regions (UTRs) of the 57 kDa protein of P. halstedii. The internal amplicon was revealed with the primer pairs F1+R1 and F2 + R2 (nested PCR). The 3'-RACE-PCR amplicon was revealed with the gene-specific primer PhE-F1 and PhE-F2 (semi-nested PCR). The 5'-RACE-PCR amplicon was revealed with the gene-specific primer PhE-R1, PhE-R2 (semi-nested PCR) and PhE-R3 (semi-nested PCR). In all RACE experiments the provided adaptor primer of the SMART™ RACE cDNA amplification kit was used.