Abstract
BRCA2 tumour-suppressor protein is well known for its role in DNA repair by homologous recombination (HR); assisting the loading of RAD51 recombinase at DNA double-strand breaks. This function is executed by the C-terminal DNA binding domain (CTD) which binds single-stranded (ss)DNA, and the BRC repeats, which bind RAD51 and modulate its assembly onto ssDNA. Paradoxically, analysis of cells resistant to DNA damaging agents missing the CTD restore HR proficiency, suggesting another domain may take over its function. Here, we identify a region in the N terminus of BRCA2 that exhibits DNA binding activity (NTD) and provide evidence for NTD promoting RAD51-mediated HR. A missense variant detected in breast cancer patients located in the NTD impairs HR stimulation on dsDNA/ssDNA junction containing substrates. These findings shed light on the function of the N terminus of BRCA2 and have implications for the evaluation of breast cancer variants.
Highlights
BRCA2 tumour-suppressor protein is well known for its role in DNA repair by homologous recombination (HR); assisting the loading of RAD51 recombinase at DNA double-strand breaks
These results suggest that the region comprising BRCA2T2 binds to ssDNA
To further validate the DNA binding activity of this region, we examined the partition of BRCA2T2 compared with BRCA2T1 between biotinylated ssDNA immobilized on streptavidin magnetic beads challenged with excess dT40 ssDNA
Summary
BRCA2 tumour-suppressor protein is well known for its role in DNA repair by homologous recombination (HR); assisting the loading of RAD51 recombinase at DNA double-strand breaks. Cells resistant to DNA damage devoid of the entire CTD can still function in HR7,8 suggesting that additional functional domains in BRCA2 could take over CTD’s function To test this hypothesis, we used protein secondary structure prediction tools (see Supplementary Methods) and identified a zinc finger (zf)-PARP like domain containing residues predicted to bind DNA in the amino (N) terminus of BRCA2 that are conserved in mammals (Supplementary Fig. 1). We used protein secondary structure prediction tools (see Supplementary Methods) and identified a zinc finger (zf)-PARP like domain containing residues predicted to bind DNA in the amino (N) terminus of BRCA2 that are conserved in mammals (Supplementary Fig. 1) This analysis prompted us to test the functional relevance of this domain. We reveal a DNA binding domain in the N terminus of BRCA2 that can stimulate RAD51-mediated homologous recombination and is mutated in breast cancer patients
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
