4Z2N: Crystal Structure Of Human Fact Spt16 Middle Domain

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 beta 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 alphaN helix, which is essential for retaining the nucleosomal DNA ends, and hence facilitates DNA stripping from histone.
PDB ID: 4Z2NDownload
MMDB ID: 137205
PDB Deposition Date: 2015/3/30
Updated in MMDB: 2016/04
Experimental Method:
x-ray diffraction
Resolution: 1.92  Å
Source Organism:
Similar Structures:
Biological Unit for 4Z2N: monomeric; determined by author
Molecular Components in 4Z2N
Label Count Molecule
Protein (1 molecule)
Fact Complex Subunit Spt16(Gene symbol: SUPT16H)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB