Advances on structural mechanisms of ubiquitinated nucleosome complexes

The ubiquitination of nucleosome histones (H2A, H2B, H3, H4) mediates a series of selective interactions between effector proteins and nucleosomes, and regulates the epigenetics of cells. In recent years, thanks to the development of new chemical and biological methods, sample acquisition technologies such as chemical modification of proteins, and structure observation technologies such as cryo-electron microscopy (Cryo-EM) have been well utilized. Some complex structures of ubiquitinated nucleosomes and effector proteins have been resolved, which revealed molecular mechanisms of ubiquitin regulated epigenetic process. This article summarizes the six complexes between ubiquitinated nucleosomes and effector proteins reported recently, comparatively analyzes the selective recognition and activation mechanism of effector proteins by ubiquitinated nucleosomes, and describes the key interaction sites on ubiquitinated nucleosomes.