Figure 4.

TAP-tagged RPB5 subunits interact with different polymerase classes. (A) Expression of the TbRPB5z and TbRPB5 TAP-tagged proteins in procyclic forms. Expression was induced overnight by addition of doxycycline and analyzed by Western blot with anti-TAP tag antibodies. (B) Protein extracts affinity purified from the TbRPB5 or TbRPB5z TAP tag-expressing cell lines were separated on gradient gels and stained by Sypro Ruby. The highest molecular weight bands of each purification were analyzed by mass spectrometry.