FIG 1.
CTD mutants and growth properties. (A) The CTD composition of human Rpb1. The CTD of human Rpb1 consists of 52 tandem heptapeptide repeats. Twenty-one out of 52 repeats are composed of conserved consensus Y1S2P3T4S5P6S7 repeats, and the remaining 31 repeats are less conserved. The Rpb1(1–26) expression vector contains the first half of the CTD, whereas Rpb1(27–52) contains the second half. The consensus repeats, less-conserved repeats, Rpb1 bodies without CTDs (gray boxes), and C-terminal 10-amino-acid motif are shown. (B) Growth curves of various mutant cell lines cultured in medium containing Tet. Averages from two independent experiments were plotted. Cells able to reach full confluence were split every 2 days. (C) Western blot showing the protein expression profiles of the various CTD mutants. Samples were treated with Tet (1 μg/ml) for 24 h.