2H0D

Structure of a Bmi-1-Ring1B Polycomb group ubiquitin ligase complex

Summary for 2H0D

• Entry DOI: 10.2210/pdb2h0d/pdb
• Descriptor: B lymphoma Mo-MLV insertion region, Ubiquitin ligase protein RING2, ZINC ION, ... (4 entities in total)
• Functional Keywords: polycomb, chromatin, ubiquitin ligase, histone, transcription, wpigenetics, metal binding protein-ligase complex, metal binding protein/ligase
• Biological source: Homo sapiens (human); More
• Cellular location: Nucleus : Q99496
• Total number of polymer chains: 2
• Total formula weight: 23108.65

Authors

Xu, R.M. (deposition date: 2006-05-14, release date: 2006-05-23, Last modification date: 2024-02-14)

Primary citation

Li, Z.,Cao, R.,Wang, M.,Myers, M.P.,Zhang, Y.,Xu, R.M.
Structure of a Bmi-1-Ring1B Polycomb Group Ubiquitin Ligase Complex.
J.Biol.Chem., 281:20643-20649, 2006

PubMed Abstract: Polycomb group proteins Bmi-1 and Ring1B are core subunits of the PRC1 complex, which plays important roles in the regulation of Hox gene expression, X-chromosome inactivation, tumorigenesis, and stem cell self-renewal. The RING finger protein Ring1B is an E3 ligase that participates in the ubiquitination of lysine 119 of histone H2A, and the binding of Bmi-1 stimulates the E3 ligase activity. We have mapped the regions of Bmi-1 and Ring1B required for efficient ubiquitin transfer and determined a 2.5-A structure of the Bmi-1-Ring1B core domain complex. The structure reveals that Ring1B "hugs" Bmi-1 through extensive RING domain contacts and its N-terminal tail wraps around Bmi-1. The two regions of interaction have a synergistic effect on the E3 ligase activity. Our analyses suggest a model where the Bmi-1-Ring1B complex stabilizes the interaction between the E2 enzyme and the nucleosomal substrate to allow efficient ubiquitin transfer.

PubMed: 16714294
DOI: 10.1074/jbc.M602461200

Experimental method

X-RAY DIFFRACTION (2.5 Å)