This domain is found in the protein Sgf73/Sca7 which is a component of the multihistone acetyltransferase complexes SAGA and SILK. This domain is also found in Ataxin-7, a human protein which in its polyglutamine expanded pathological form, is responsible for the neurodegenerative disease spinocerebellar ataxia 7 (SCA7). Ataxin-7 is an integral component of the mammalian SAGA-like complexes, the TATA-binding protein-free TAF-containing complex (TFTC) and the SPT3/TAF9/GCN5 acetyltransferase complex (STAGA). This domain is a minimal domain in ataxin-7-like proteins that is required for interaction with TFTC/STAGA subunits and is conserved highly through evolution. The domain contains a conserved Cys(3)His motif that binds zinc, thus indicating this to be a new zinc-binding domain.