Figure 6.

BRCA2_2213–2342 interacts with HSF2BP, a protein essential for meiotic HR. (A) BRCA2_2213–2342 conservation profile, as calculated in Figure 1. Regions encoded by exons 12 and 13 are boxed in blue and green, respectively. (B) NMR analysis of BRCA2_2213–2342 interaction with the Armadillo domain of HSF2BP (HSF2BP_ARM) [54]. 2D ¹H-¹⁵N HSQC spectra were recorded on ¹⁵N-labeled BRCA2_2213-2342, either free or in the presence of HSF2BP_ARM (1:1 ratio, knowing that 1 BRCA2 peptide binds to 2 HSF2BP_ARM), at 950 MHz and 283 K. Ratios of peak intensities in the two conditions are plotted as a function of BRCA2 residue number. The points and curve fragments in blue and green correspond to residues encoded by exons 12 and 13 of BRCA2, respectively. (C) Crystal structure of the complex between BRCA2_2291–2342 and HSF2BP_ARM, illustrating how the HSF2BP_ARM dimers, formed by chains A (grey) and D (green) and chains B (yellow) and C (cyan), are held together through their interactions with the two BRCA2 peptides (magenta) [54]. The HSF2BP_ARM domains are represented as both cartoon and surface, whereas the BRCA2 peptides are displayed as tubes. In the zoom view, only one BRCA2 peptide is shown. Its N-terminal region interacts with one HSF2BP_ARM domain through motif 1 (blue sticks), and its C-terminal region interacts with another HSF2BP_ARM domain through motif 2 (green sticks). Only the side chains of residues that are conserved in BRCA2 from fishes to mammals and are similar between motifs 1 and 2 are displayed. (D) Sequence of BRCA2 motifs 1 and 2, encoded by exons 12 and 13, respectively. Each motif binds to one HSF2BP_ARM. Residues conserved in BRCA2 from fishes to mammals and similar between motifs 1 and 2 are colored in blue and green, respectively.