?|cl25407: ClassIIa_HDAC_Gln-rich-N Superfamily
Glutamine-rich N-terminal helical domain of various Class IIa histone deacetylases (HDAC4, HDAC5 and HDCA9)This superfamily consists of a glutamine-rich N-terminal helical extension to certain Class IIa histone deacetylases (HDACs), including HDAC4, HDAC5 and HDAC9; it is missing in HDAC7. It is referred to as the glutamine-rich domain, and confers responsiveness to calcium signals and mediates interactions with transcription factors and cofactors. This domain is able to repress transcription independently of the HDAC's C-terminal, zinc-dependent catalytic domain. It has many intra- and inter-helical interactions which are possibly involved in reversible assembly and disassembly of proteins. HDACs regulate diverse cellular processes through enzymatic deacetylation of histone as well as non-histone proteins, in particular deacetylating N(6)-acetyl-lysine residues.