Fig. 5: Mechanism model proposed for the co-regulation of ubH2B and FACT on gene transcription.

The preferable binding of FACT on ubH2B-nucleosome forms a stable altered nucleosome state and provides a key platform for transcriptional activation. I. ubH2B promotes the binding of FACT to deposit the H2A-ubH2B dimer to form a stable FACT-ubH2B-nucleosome state. II. Ubiquitination of H2B impairs the stability of nucleosome, but helps to recruit FACT to maintain a stable structural state at nucleosome level.