Component of the transcription regulatory histone acetylation (HAT) complex SAGA, a multiprotein complex that activates transcription by remodeling chromatin and mediating histone acetylation and deubiquitination. Within the SAGA complex, participates in a subcomplex that specifically deubiquitinates histone H2B. The SAGA complex is recruited to specific gene promoters by activators, where it is required for transcription. Component of some SAGA transcription coactivator-HAT complexes. Within the SAGA complex, participates in a subcomplex of SAGA called the DUB module (deubiquitination module) (By similarity). By bursicon. The long N-terminal helix forms part of the 'assembly lobe' of the SAGA deubiquitination module. The C-terminal SGF11-type zinc-finger domain forms part of the 'catalytic lobe' of the SAGA deubiquitination module. Belongs to the SGF11 family.