Fig. 1

A–E Breast cancer susceptibility protein 2 (Brca2) is conserved in Plasmodium berghei (Pb). A Schematic representation of PbBrca2 protein domains relative to human, Trypanosoma brucei, and Leishmania infantum BRCA2 and Ustilago maydis Brh2. Predicted BRC repeats, tower and oligonucleotide/oligosaccharide-binding (OB)-fold domains, and nuclear localization signals are shown. For human BRCA2, PALB2, DMC1, and DNA repair protein Rad51 homolog 1 (Rad51)-binding domains (BD) are shown. B Alignment of human BRCA2 BRC repeat 4 and three PbBrca2 BRC repeats. Magenta boxes indicate that the phenylalanine residues F1524 and F1546 are required for interaction with Rad51. C Interaction activity of PbBrca2 BRC repeats with P. berghei, human, and Saccharomyces cerevisiae Rad51 and P. berghei Dmc1 was tested by mammalian two-hybrid assay; 293T cells were transfected with DNA-binding domain fused with PbBrca2 BRC repeats, transactivation domain (TAD) fused with Rad51 or Dmc1, and luciferase reporter and normalization plasmids. Relative luciferase activity normalized with Renilla luciferase activity. Comparison of mean values was performed using the F-test followed by Student’s t-test; * P < 0.05 (vs. paired TAD-fused protein-expressing samples). D Expression levels of TAD-fused proteins in mammalian two-hybrid assay were confirmed. All TAD-fused proteins are expressed. E Structural representation of the amino acid substitutions in human Rad51. The substituted amino acids are important for interaction with human BRC repeat 4 and differ from PbRad51. The three-dimensional structure based on human Rad51 and BRC repeat 4 crystal structure was predicted using Chimera software. Number of contacts between BRC repeat 4 and Rad51 decrease in the case of all four substitutions