This entry includes the nucleosome-remodeling factor subunits BPTF (vertebrates) and NURF301 (Drosophila melanogaster), which are components of the NURF (nucleosome-remodeling factor) complex [, ]. The NURF complex catalyzes ATP-dependent nucleosome sliding and facilitates transcription of chromatin []. The HMGA/HMGI(Y)-like DNA-binding site of NURF301 facilitates nucleosome sliding []. BPTF binds histone H3K4me3 via its PHD zinc finger domain [], and interacts with the myc-associated zinc finger protein MAZ, altering its transcriptional activity, []and the Kelch-like Ech-associated protein KEAP1 [].
This entry represents the WHIM2 domain found in diverse eukaryotic chromatin proteins, such as animal BAZ/WAL and BPTF proteins, plant RLT, and yeast Itc1. This domain contains the D-TOX E motif (also known as the Williams-Beuren syndrome DDT (WSD) motif) that is conserved from yeasts to animals [, , ].WHIM2 domain is a conserved alpha helical motif that along with the WHIM1 and WHIM3 motifs, and the DDT domain comprise an alpha helical module found in diverse eukaryotic chromatin proteins []. Based on the Ioc3 structure, this module is inferred to interact with nucleosomal linker DNA and the SLIDE domain of ISWI proteins [, ]. The resulting complex forms a protein ruler that measures out the spacing between two adjacent nucleosomes []. The acidic residue from the GxD signature of WHIM2 is a major determinant of the interaction between the ISWI and WHIM motifs. The N-terminal portion of the WHIM2 motif also contacts the inter-nucleosomal linker DNA. The module shows a great domain architectural diversity and is often combined with other modified histone peptide recognizing and DNA binding domains, some of which discriminate methylated DNA [].
