Mechanistic insights into nucleosomal H2B monoubiquitylation mediated by yeast Bre1-Rad6 and its human homolog RNF20/RNF40-hRAD6A.
Mol Cell
; 83(17): 3080-3094.e14, 2023 09 07.
Article
em En
| MEDLINE
| ID: mdl-37633270
ABSTRACT
Histone H2B monoubiquitylation plays essential roles in chromatin-based transcriptional processes. A RING-type E3 ligase (yeast Bre1 or human RNF20/RNF40) and an E2 ubiquitin-conjugating enzyme (yeast Rad6 or human hRAD6A), together, precisely deposit ubiquitin on H2B K123 in yeast or K120 in humans. Here, we developed a chemical trapping strategy and successfully captured the transient structures of Bre1- or RNF20/RNF40-mediated ubiquitin transfer from Rad6 or hRAD6A to nucleosomal H2B. Our structures show that Bre1 and RNF40 directly bind nucleosomal DNA, exhibiting a conserved E3/E2/nucleosome interaction pattern from yeast to humans for H2B monoubiquitylation. We also find an uncanonical non-hydrophobic contact in the Bre1 RING-Rad6 interface, which positions Rad6 directly above the target H2B lysine residue. Our study provides mechanistic insights into the site-specific monoubiquitylation of H2B, reveals a critical role of nucleosomal DNA in mediating E3 ligase recognition, and provides a framework for understanding the cancer-driving mutations of RNF20/RNF40.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Nucleossomos
/
Proteínas de Saccharomyces cerevisiae
Limite:
Humans
Idioma:
En
Revista:
Mol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
China