Dss1 regulates interaction of Brh2 with DNA.

TitleDss1 regulates interaction of Brh2 with DNA.
Publication TypeJournal Article
Year of Publication2009
AuthorsZhou Q, Mazloum N, Mao N, Kojic M, Holloman WK
Date Published2009 Dec 22
KeywordsBRCA2 Protein, DNA Damage, DNA Repair, DNA, Fungal, DNA-Binding Proteins, Fungal Proteins, Peptide Fragments, Rad51 Recombinase, Recombination, Genetic, Ustilago

Brh2, the BRCA2 homologue in Ustilago maydis, plays a crucial role in homologous recombination by controlling Rad51. In turn, Brh2 is governed by Dss1, an intrinsically disordered protein that forms a tight complex with the C-terminal region of Brh2. This region of the protein associating with Dss1 is highly conserved in sequence and by comparison with mammalian BRCA2 corresponds to a part of the DNA binding domain with characteristic OB folds. The N-terminal region of Brh2 harbors a less-defined but powerful DNA binding site, the activity of which is revealed upon deletion of the C-terminal region. Full-length Brh2 complexed with Dss1 binds DNA slowly, while the N-terminal fragment binds quickly. The DNA binding activity of full-length Brh2 appears to correlate with dissociation of Dss1. Addition of Dss1 to the heterotypic Brh2-Dss1 complex attenuates DNA binding activity, but not by direct competition for the N-terminal DNA binding site. Conversely, the Brh2-Dss1 complex dissociates more quickly when DNA is present. These findings suggest a model in which binding of Brh2 to DNA is subject to allosteric regulation by Dss1.

Alternate JournalBiochemistry
PubMed ID19919104
PubMed Central IDPMC2795026
Grant ListGM42482 / GM / NIGMS NIH HHS / United States
GM79859 / GM / NIGMS NIH HHS / United States
R01 GM042482-18 / GM / NIGMS NIH HHS / United States
R01 GM042482-19 / GM / NIGMS NIH HHS / United States
R01 GM079859-02 / GM / NIGMS NIH HHS / United States
R01 GM079859-03 / GM / NIGMS NIH HHS / United States

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