Figure 2.

CHD1 and ISWI family remodelers share functional domains. Common domains are color-coded. The N-terminal double chromodomains of CHD1 and AutoN ISWI enzymes both function to prevent ATP hydrolysis when the enzyme is not bound to nucleosomes. The chromodomain (chromatin organization modifier) is a highly conserved sequence found in many eukaryotic proteins and enzymes with chromatin functions. The DEXD ATPase /Helicase domains form the enzymatic core of these remodelers that is deeply conserved both in sequence and function and is found in all chromatin remodelers studied to date. The Neg C domains of ISWI and CHD1 prevent translocation when the enzyme is not engaged with extranucleosomal DNA. The C-terminal domains participate in extranucleosomal DNA binding. SANT (Swi3, Ada2, N-Cor, and TFIIIB) is a DNA binding domain originally identified based on homology with Myb proteins and found in many chromatin regulatory proteins [106]. SLIDE (SANT-Like ISWI Domain) is very similar to SANT, structurally, and these two DNA-binding domains are shared in CHD1 and ISWI proteins [20, 23, 106]. CHD1 contains a unique domain called HL1 (Helical Linker 1) and contains residues important for DNA-binding [22, 23]. The ISWI C-terminus also contains a HAND domain (named because the structure resembles an open hand) which is connected to the ATPase domain through a long linker [20].