?
histone fold domain (HFD) superfamily The histone fold domain (HFD) is a structurally conserved interaction motif involved in heterodimerization of the core histones and their assembly into the nucleosome octamer. Histone fold heterodimers play crucial roles in gene regulation. The minimal HFD consists of three alpha helices connected by two short, unstructured loops. The HFD is found in core histones, TATA box-binding protein-associated factors (TAFs), and many other transcription factors. HFD plays a role in the nucleosomal core particle by conserving histone interactions; these contain more than one HFD. The structure of the nucleosome core particle has two modes that have the largest interaction surfaces, and these are the H3-H4 and H2A-H2B heterodimer interactions. Several TAFs interact via histone-fold (HF) motifs. Five HF-containing TAF pairs have been described in transcription factor II D (TFIID): TAF6-TAF9, TAF4-TAF12, TAF11-TAF13, TAF8-TAF10 and TAF3-TAF10.
|