Fig. 2. Locations of the positioned nucleosome IV, α2 operator and poly(dA)⋅poly(dT) inserts in TALS and its derivative minichromosomes as described (Shimizu et al., 1991; Kladde and Simpson, 1994). The SacI and DraIII sites are at 1460 and 1412 m.u. (map units), respectively, in nucleosome IV as shown by the shaded ellipse. The α2 operator and poly(dA)⋅poly(dT) tracts are shown as hatched and shaded boxes, respectively. The polylinker attached with the A₁₅TATA₁₆ insert is indicated by white boxes (see Materials and methods).