(A) Comparison of inactive and active states of Saccharomyces cerevisiae Chd1. Left: in its nucleosome ligand-free state (PDB 3MWY, Hauk et al., 2010) the two ATPase lobes of ScChd1 are misaligned and separated due to the binding of the chromodomain (yellow surface). Right: upon the activation by binding of chromodomains to a nucleosomal substrate (here omitted), the block on lobe 2 is released, enabling proper alignment of both lobes for ATP hydrolysis (PDB 5O9G, Farnung et al., 2017). (B) Other Swi2/Snf2 domain structures representing auto-inhibited conformations: Myceliophthora thermophila ISWI (PDB 5JXR, Yan et al., 2016), Myceliophthora thermophila Snf2 (PDB 5HZR, Xia et al., 2016), Sulpholobus solfataricus Rad54 (PDB 1Z6A, Dürr et al., 2005), and Chaetomium thermophilum Mot1 (PDB 6G7E, this study). All panels show the same view with respect to lobe 1, thereby highlighting distinct positions of lobe 2 in all structures. In all panels, lobe 1 and 2 are represented as cartoons color-coded as in Figure 1. Auxiliary domains adjacent to the ATPase domain are shown as yellow surfaces.