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The histone chaperone FACT modulates nucleosome structure by tethering its components.

ABSTRACT: Human FAcilitates Chromatin Transcription (hFACT) is a conserved histone chaperone that was originally described as a transcription elongation factor with potential nucleosome assembly functions. Here, we show that FACT has moderate tetrasome assembly activity but facilitates H2A-H2B deposition to form hexasomes and nucleosomes. In the process, FACT tethers components of the nucleosome through interactions with H2A-H2B, resulting in a defined intermediate complex comprising FACT, a histone hexamer, and DNA. Free DNA extending from the tetrasome then competes FACT off H2A-H2B, thereby promoting hexasome and nucleosome formation. Our studies provide mechanistic insight into how FACT may stabilize partial nucleosome structures during transcription or nucleosome assembly, seemingly facilitating both nucleosome disassembly and nucleosome assembly.

SUBMITTER: Wang T

PROVIDER: S-EPMC6238592 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature

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The histone chaperone FACT modulates nucleosome structure by tethering its components.

Wang Tao T Liu Yang Y Edwards Garrett G Krzizike Daniel D Scherman Hataichanok H Luger Karolin K

Life science alliance 20180710 4

Human FAcilitates Chromatin Transcription (hFACT) is a conserved histone chaperone that was originally described as a transcription elongation factor with potential nucleosome assembly functions. Here, we show that FACT has moderate tetrasome assembly activity but facilitates H2A-H2B deposition to form hexasomes and nucleosomes. In the process, FACT tethers components of the nucleosome through interactions with H2A-H2B, resulting in a defined intermediate complex comprising FACT, a histone hexam ...[more]

PMID: 30456370

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The histone chaperone FACT: structural insights and mechanisms for nucleosome reorganization.

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