Edwards, Ross A. Lee, Megan S. Tsutakawa, Susan E. Williams, R. Scott Tainer, John A. N. Mark Glover, J. The BARD1 C-Terminal Domain Structure and Interactions with Polyadenylation Factor CstF-50 The BARD1 N-terminal RING domain binds BRCA1 while the BARD1 C-terminal ankyrin and tandem BRCT repeat domains bind CstF-50 to modulate mRNA processing and RNAP II stability in response to DNA damage. Here we characterize the BARD1 structural biochemistry responsible for CstF-50 binding. The crystal structure of the BARD1 BRCT domain uncovers a degenerate phosphopeptide binding pocket lacking the key arginine required for phosphopeptide interactions in other BRCT proteins. Small angle X-ray scattering together with limited proteolysis results indicates that ankyrin and BRCT domains are linked by a flexible tether and do not adopt a fixed orientation relative to one another. Protein pull-down experiments utilizing a series of purified BARD1 deletion mutants indicate that interactions between the CstF-50 WD-40 domain and BARD1 involve the ankyrin-BRCT linker but do not require ankyrin or BRCT domains. The structural plasticity imparted by the ANK-BRCT linker helps to explain the regulated assembly of different protein BARD1 complexes with distinct functions in DNA damage signaling including BARD1-dependent induction of apoptosis plus p53 stabilization and interactions. BARD1 architecture and plasticity imparted by the ANK-BRCT linker are suitable to allow the BARD1 C-terminus to act as a hub with multiple binding sites to integrate diverse DNA damage signals directly to RNA polymerase. phosphopeptide binding pocket;WD;CstF;p 53 stabilization;BARD 1 architecture;DNA damage signals;protein BARD 1 complexes;BRCA;BRCT domains;DNA damage;BARD 1 BRCT domain uncovers;BARD 1 deletion mutants;BARD 1;RNAP II stability 2015-12-16
    https://acs.figshare.com/articles/journal_contribution/The_BARD1_C_Terminal_Domain_Structure_and_Interactions_with_Polyadenylation_Factor_CstF_50/2010990
10.1021/bi801115g.s001