Breast cancer type 2 susceptibility protein, helical domain (IPR015252)

Short name: BRCA2_hlx

Domain relationships



The mechanism of double-strand break repair (DSBR) is evolutionarily conserved and can be divided into two main pathways: homologous recombination (HR) and non-homologous end joining (NHEJ). NHEJ involves the ligation of broken DNA ends, requires little or no sequence homology and may be mutagenic. HR can occur conservatively by gene conversion using a homologous strand of DNA as a template or non-conservatively by single-strand annealing, which takes place between repeat sequences and can lead to the loss of intervening genomic DNA or translocations. BRCA2 cancer susceptibility protein functions in double-strand DNA break repair by homologous recombination [PMID: 17822964]. Double-strand breaks in DNA elicit a coordinated response that results in either repair of the damage or elimination of the cell. Mutations in Brca2 lead to various types of cancer, and also give rise to the multi-faceted Fanconi anaemia syndrome [PMID: 17768402]. BRCA2 is an essential component of the homologous recombination repair pathway and the Fanconi Anaemia complex [PMID: 17786054].

This entry represents a domain found in BRCA2 proteins. This domain adopts a helical structure, consisting of a four-helix cluster core (alpha 1, alpha 8, alpha 9, alpha 10) and two successive beta-hairpins (beta 1 to beta 4). An approximately 50-amino acid segment that contains four short helices (alpha 2 to alpha 4), meanders around the surface of the core structure. In BRCA2, the alpha 9 and alpha 10 helices pack with BRCA-2_OB1 (IPR015187) through van der Waals contacts involving hydrophobic and aromatic residues, and also through side-chain and backbone hydrogen bonds. This domain binds the 70-amino acid DSS1 (deleted in split-hand/split foot syndrome) protein, which was originally identified as one of three genes that map to a 1.5-Mb locus deleted in an inherited developmental malformation syndrome [PMID: 12228710].

GO terms

Biological Process

GO:0006310 DNA recombination
GO:0000724 double-strand break repair via homologous recombination

Molecular Function

GO:0003697 single-stranded DNA binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.