4zux
From Proteopedia
SAGA DUB module Ubp8/Sgf11/Sus1/Sgf73 bound to ubiqitinated nucleosome
Structural highlights
FunctionH2A1_XENLA Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. Publication Abstract from PubMedMonoubiquitinated histone H2B plays multiple roles in transcription activation. H2B is deubiquitinated by the Spt-Ada-Gcn5 acetyltransferase (SAGA) coactivator, which contains a four-protein subcomplex known as the deubiquitinating (DUB) module. The crystal structure of the Ubp8/Sgf11/Sus1/Sgf73 DUB module bound to a ubiquitinated nucleosome reveals that the DUB module primarily contacts H2A/H2B, with an arginine cluster on the Sgf11 zinc finger domain docking on the conserved H2A/H2B acidic patch. The Ubp8 catalytic domain mediates additional contacts with H2B, as well as with the conjugated ubiquitin. We find that the DUB module deubiquitinates H2B both in the context of the nucleosome and in H2A/H2B dimers complexed with the histone chaperone, FACT, suggesting that SAGA could target H2B at multiple stages of nucleosome disassembly and reassembly during transcription. Structural basis for histone H2B deubiquitination by the SAGA DUB module.,Morgan MT, Haj-Yahya M, Ringel AE, Bandi P, Brik A, Wolberger C Science. 2016 Feb 12;351(6274):725-8. doi: 10.1126/science.aac5681. PMID:26912860[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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