Fig. 1: The AT-hook of Snf2 is required for efficient ATP hydrolysis and nucleosome mobilization by the yeast SWI/SNF complex.

a The ___domain organization of the catalytic subunit of yeast Snf2 is shown including the two AT hook motifs at the C-terminus. The two AT-hooks of yeast Snf2 are removed by deleting residues 1443-1539 in yeast SNF2. b The amino acid sequence is shown for the two AT-hooks in Snf2 of S. cerevisiae and its homologs in zebra fish (D.r.), Xenopus laevis (X.l.), mouse (M.m), human (H.s.), and two fungal species Candida albicans (C.a.) and Saccharomyces bayanus (S.b). Conserved residues are highlighted in blue and yellow. c Wild (WT) and the AT-hooks deletion mutant (ΔAT) SWI/SNF complexes were immunoaffinity purified and analyzed on a 4-20% gradient SDS-PAGE. d The nucleosome mobilizing activity of WT and ΔAT SWI/SNF are compared using an electrophoretic mobility shift assay (EMSA) on a 5% native polyacrylamide gel. The reactions contained 2.5 nM 29N59 nucleosomes, 7.5 nM yeast SWI/SNF and 4.4 μM ATP and incubated for 0, 10, 20, 40, 80,160, 300 and 600 s at 30 °C (WT lanes 1-8 and ΔAT lanes 9-16). Nucleosomes were fully bound by SWI/SNF under these conditions as shown for ΔAT SWI/SNF in lane 17. e The extent of remodeling was quantitated and plotted relative to reaction time in reactions that contained 7.5 nM SWI/SNF, 2.5 nM nucleosomes and 4.4 μM ATP. f The rate of ATP hydrolyzed under the same conditions as in (e) were measured by thin layer chromatography and plotted with the amount of ATP hydrolyzed versus reaction time. Two or three replicates were performed for both (e) and (d) and individual data points are shown. Source data are provided as a Source Data File.