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Valieva ME , Armeev GA , Kudryashova KS , Gerasimova NS , Shaytan AK , Kulaeva OI , McCullough LL , Formosa T , Georgiev PG , Kirpichnikov MP , Studitsky VM , Feofanov AV
Large-scale ATP-independent nucleosome unfolding by a histone chaperone
Nat Struct Mol Biol. 2016 Dec;23(12) :1111-1116
PMID: 27820806    PMCID: PMC5518926    URL: https://www.ncbi.nlm.nih.gov/pubmed/27820806
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DNA accessibility to regulatory proteins is substantially influenced by nucleosome structure and dynamics. The facilitates chromatin transcription (FACT) complex increases the accessibility of nucleosomal DNA, but the mechanism and extent of its nucleosome reorganization activity are unknown. Here we determined the effects of FACT from the yeast Saccharomyces cerevisiae on single nucleosomes by using single-particle Forster resonance energy transfer (spFRET) microscopy. FACT binding results in dramatic ATP-independent, symmetrical and reversible DNA uncoiling that affects at least 70% of the DNA within a nucleosome, occurs without apparent loss of histones and proceeds via an 'all-or-none' mechanism. A mutated version of FACT is defective in uncoiling, and a histone mutation that suppresses phenotypes caused by this FACT mutation in vivo restores the uncoiling activity in vitro. Thus, FACT-dependent nucleosome unfolding modulates the accessibility of nucleosomal DNA, and this activity is an important function of FACT in vivo.
Valieva, Maria E Armeev, Grigoriy A Kudryashova, Kseniya S Gerasimova, Nadezhda S Shaytan, Alexey K Kulaeva, Olga I McCullough, Laura L Formosa, Tim Georgiev, Pavel G Kirpichnikov, Mikhail P Studitsky, Vasily M Feofanov, Alexey V eng 2016/11/08 06:00 Nat Struct Mol Biol. 2016 Dec;23(12):1111-1116. doi: 10.1038/nsmb.3321. Epub 2016 Nov 7.