(A–D) Determination of rate constants (kobs) from remodeling assays for ISWI+6, ISWI2RA and ISWI+6; 2RA. Shown are exemplary time courses on nucleosomal arrays containing wild-type (A,C) and tail-less H4 (B,D). Data were fit to a single exponential function to extract the rate constant kobs. (E) Rate constants for remodeling of ISWI variants used in this study (all 300 nM). Errors are s.d. (n ≥ 3) for ISWIWT, ISWIΔppHSA, and ISWI+6 and minimal and maximal values of two independent measurements for all other variants. Samples, in which the enzyme concentration was not saturating, are indicated (§). Data marked with asterisks (*) were replotted from previous figures for better overview.