3h8h is a 1 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
[RING2_HUMAN] E3 ubiquitin-protein ligase that mediates monoubiquitination of 'Lys-119' of histone H2A, thereby playing a central role in histone code and gene regulation. H2A 'Lys-119' ubiquitination gives a specific tag for epigenetic transcriptional repression and participates in X chromosome inactivation of female mammals. May be involved in the initiation of both imprinted and random X inactivation. Essential component of a Polycomb group (PcG) multiprotein PRC1-like complex, a complex class required to maintain the transcriptionally repressive state of many genes, including Hox genes, throughout development. PcG PRC1 complex acts via chromatin remodeling and modification of histones, rendering chromatin heritably changed in its expressibility. E3 ubiquitin-protein ligase activity is enhanced by BMI1/PCGF4. Acts as the main E3 ubiquitin ligase on histone H2A of the PRC1 complex, while RING1 may rather act as a modulator of RNF2/RING2 activity.[1][2][3][4][5]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Polycomb group (PcG) proteins are a special set of repressive transcription factors involved in epigenetic modifications of chromatin. They form two functionally distinct groups of catalytically active complexes: Polycomb repressive complex 1 (PRC1) and 2 (PRC2). The PRC1 complex is an important yet poorly characterized multiprotein histone ubiquitylation machine responsible for maintaining transcriptionally silent states of genes through histone H2A K119 modification. The Ring domain containing subunits of PRC1 also have substrate-targeting domains that interact with Cbx proteins, which have been implicated in chromatin and RNA binding. In this work, we present a high resolution structure of the C-terminal domain of Ring1B, revealing a variant ubiquitin-like fold with a distinct conserved surface region. On the basis of crystal structure and mutational analysis of this domain we show that the conserved surface is responsible for interaction with Cbx members of the PRC1 and homodimer formation. These data suggest a mechanism by which Ring1B serves as an adaptor that mediates binding between the members of the PRC1 complex and the nucleosome.
Ring1B contains a ubiquitin-like docking module for interaction with Cbx proteins.,Bezsonova I, Walker JR, Bacik JP, Duan S, Dhe-Paganon S, Arrowsmith CH Biochemistry. 2009 Nov 10;48(44):10542-8. PMID:19791798[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
↑Lee SJ, Choi JY, Sung YM, Park H, Rhim H, Kang S. E3 ligase activity of RING finger proteins that interact with Hip-2, a human ubiquitin-conjugating enzyme. FEBS Lett. 2001 Aug 10;503(1):61-4. PMID:11513855
↑Wang H, Wang L, Erdjument-Bromage H, Vidal M, Tempst P, Jones RS, Zhang Y. Role of histone H2A ubiquitination in Polycomb silencing. Nature. 2004 Oct 14;431(7010):873-8. Epub 2004 Sep 22. PMID:15386022 doi:10.1038/nature02985
↑Cao R, Tsukada Y, Zhang Y. Role of Bmi-1 and Ring1A in H2A ubiquitylation and Hox gene silencing. Mol Cell. 2005 Dec 22;20(6):845-54. PMID:16359901 doi:10.1016/j.molcel.2005.12.002
↑Li Z, Cao R, Wang M, Myers MP, Zhang Y, Xu RM. Structure of a Bmi-1-Ring1B polycomb group ubiquitin ligase complex. J Biol Chem. 2006 Jul 21;281(29):20643-9. Epub 2006 May 18. PMID:16714294 doi:10.1074/jbc.M602461200
↑Wang R, Taylor AB, Leal BZ, Chadwell LV, Ilangovan U, Robinson AK, Schirf V, Hart PJ, Lafer EM, Demeler B, Hinck AP, McEwen DG, Kim CA. Polycomb group targeting through different binding partners of RING1B C-terminal domain. Structure. 2010 Aug 11;18(8):966-75. PMID:20696397 doi:10.1016/j.str.2010.04.013
↑Bezsonova I, Walker JR, Bacik JP, Duan S, Dhe-Paganon S, Arrowsmith CH. Ring1B contains a ubiquitin-like docking module for interaction with Cbx proteins. Biochemistry. 2009 Nov 10;48(44):10542-8. PMID:19791798 doi:10.1021/bi901131u
