A Structural Model of the Endogenous Human BAF Complex Informs Disease Mechanisms.

Publication Type Academic Article
Authors Mashtalir N, Suzuki H, Farrell D, Sankar A, Luo J, Filipovski M, D'Avino A, St Pierre R, Valencia A, Onikubo T, Roeder R, Han Y, He Y, Ranish J, DiMaio F, Walz T, Kadoch C
Journal Cell
Volume 183
Issue 3
Pagination 802-817.e24
Date Published 10/13/2020
ISSN 1097-4172
Keywords Disease, Models, Molecular, Multiprotein Complexes
Abstract Mammalian SWI/SNF complexes are ATP-dependent chromatin remodeling complexes that regulate genomic architecture. Here, we present a structural model of the endogenously purified human canonical BAF complex bound to the nucleosome, generated using cryoelectron microscopy (cryo-EM), cross-linking mass spectrometry, and homology modeling. BAF complexes bilaterally engage the nucleosome H2A/H2B acidic patch regions through the SMARCB1 C-terminal α-helix and the SMARCA4/2 C-terminal SnAc/post-SnAc regions, with disease-associated mutations in either causing attenuated chromatin remodeling activities. Further, we define changes in BAF complex architecture upon nucleosome engagement and compare the structural model of endogenous BAF to those of related SWI/SNF-family complexes. Finally, we assign and experimentally interrogate cancer-associated hot-spot mutations localizing within the endogenous human BAF complex, identifying those that disrupt BAF subunit-subunit and subunit-nucleosome interfaces in the nucleosome-bound conformation. Taken together, this integrative structural approach provides important biophysical foundations for understanding the mechanisms of BAF complex function in normal and disease states.
DOI 10.1016/j.cell.2020.09.051
PubMed ID 33053319
PubMed Central ID PMC7717177
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