FACT maintains nucleosomes around promoters and opposes to the spreading of chromatin factors, thereby playing a major role in chromatin architecture [ChIP-seq]

However, studying it in higher eukaryotes is challenging due to the difficulty to manipulate nucleosomes in vivo and reconstitute their large higher-order chromatin domains in vitro. Facilitates chromatin transcription (FACT) is a H2A/B histone chaperone that displaces and re-assembles histones, being important for processes such as transcription.

Recent studies report a minor role of FACT in chromatin architecture. Here, we studied chromatin organization upon rapid FACT degradation employing a multidimensional 3C technique with base-pair resolution (MCC-u) and genomic approaches. FACT loss leads to nucleosome depletion around active promoters, nano-scale domain collapse and emergence of larger nucleosome-free regions with increased protein binding.