(a) PIC excluding the kinase domain (TFIIK) was assembled on SNR20* short (adjacent to the 2.7-kbp downstream handle sequence) and sedimented on a glycerol gradient; fractions were analyzed by SDS-PAGE. (b) The results from fraction 12, annotated in detail, indicate that all PIC components were retained, confirming that the complex reconstituted fully from the component proteins. The subunit(s) of pol II are labeled in black, TFIIF in blue, TFIIE in magenta, TFIIH in orange, TFIIA in cyan, TFIIB in red, TBP in light green, and Sub1 in dark green. TFIIK (3-subunits) was later added to the PIC.