The structural plasticity of SCA7 domains defines their differential nucleosome-binding properties.
Fiche publication
Date publication
août 2010
Auteurs
Membres identifiés du Cancéropôle Est :
Dr HAMICHE Ali, Dr KIEFFER Bruno, Dr ROMIER Christophe, Dr TORA Laszlo
Tous les auteurs :
Bonnet J, Wang YH, Spedale G, Atkinson RA, Romier C, Hamiche A, Pijnappel WW, Timmers HT, Tora L, Devys D, Kieffer B
Lien Pubmed
Résumé
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.
Référence
EMBO Rep. 2010 Aug;11(8):612-8