4Z2N

Crystal structure of human FACT SPT16 middle domain

Summary for 4Z2N

• Entry DOI: 10.2210/pdb4z2n/pdb
• Related: 4Z2M
• Descriptor: FACT complex subunit SPT16 (2 entities in total)
• Functional Keywords: transcription
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 1
• Total formula weight: 33372.19

Authors

Tsunaka, Y.,Fujiwara, Y.,Oyama, T.,Hirose, S.,Morikawa, K. (deposition date: 2015-03-30, release date: 2016-03-09, Last modification date: 2023-11-08)

Primary citation

Tsunaka, Y.,Fujiwara, Y.,Oyama, T.,Hirose, S.,Morikawa, K.
Integrated molecular mechanism directing nucleosome reorganization by human FACT.
Genes Dev., 30:673-686, 2016

PubMed Abstract: Facilitates chromatin transcription (FACT) plays essential roles in chromatin remodeling during DNA transcription, replication, and repair. Our structural and biochemical studies of human FACT-histone interactions present precise views of nucleosome reorganization, conducted by the FACT-SPT16 (suppressor of Ty 16) Mid domain and its adjacent acidic AID segment. AID accesses the H2B N-terminal basic region exposed by partial unwrapping of the nucleosomal DNA, thereby triggering the invasion of FACT into the nucleosome. The crystal structure of the Mid domain complexed with an H3-H4 tetramer exhibits two separate contact sites; the Mid domain forms a novel intermolecular β structure with H4. At the other site, the Mid-H2A steric collision on the H2A-docking surface of the H3-H4 tetramer within the nucleosome induces H2A-H2B displacement. This integrated mechanism results in disrupting the H3 αN helix, which is essential for retaining the nucleosomal DNA ends, and hence facilitates DNA stripping from histone.

PubMed: 26966247
DOI: 10.1101/gad.274183.115

Experimental method

X-RAY DIFFRACTION (1.923 Å)