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The structural plasticity of SCA7 domains defines their differential nucleosome-binding properties.

ABSTRACT: SAGA (Spt-Ada-Gcn5 acetyltransferase), a coactivator complex involved in chromatin remodelling, harbours both histone acetylation and deubiquitination activities. ATXN7/Sgf73 and ATXN7L3, two subunits of the SAGA deubiquitination module, contain an SCA7 domain characterized by an atypical zinc-finger. We show that the yeast Sgf73-SCA7 domain is not required to recruit Sgf73 into SAGA. Instead, it binds to nucleosomes, a property that is conserved in the human ATXN7-SCA7 domain but is lost in the ATXN7L3 domain. The solution structures of the SCA7 domain of both ATXN7 and ATXN7L3 reveal a new, common zinc-finger motif at the heart of two distinct folds, providing a molecular basis for the observed functional differences.

SUBMITTER: Bonnet J

PROVIDER: S-EPMC2920448 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature

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The structural plasticity of SCA7 domains defines their differential nucleosome-binding properties.

Bonnet Jacques J Wang Ying-Hui YH Spedale Gianpiero G Atkinson R Andrew RA Romier Christophe C Hamiche Ali A Pijnappel W W M Pim WW Timmers H Th Marc HT Tora László L Devys Didier D Kieffer Bruno B

EMBO reports 20100716 8

SAGA (Spt-Ada-Gcn5 acetyltransferase), a coactivator complex involved in chromatin remodelling, harbours both histone acetylation and deubiquitination activities. ATXN7/Sgf73 and ATXN7L3, two subunits of the SAGA deubiquitination module, contain an SCA7 domain characterized by an atypical zinc-finger. We show that the yeast Sgf73-SCA7 domain is not required to recruit Sgf73 into SAGA. Instead, it binds to nucleosomes, a property that is conserved in the human ATXN7-SCA7 domain but is lost in the ...[more]

PMID: 20634802

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