Figure 6.
The TFIIH kinase Kin28 is required for CTD Ser 5 phosphorylation and capping enzyme recruitment to promoters in vivo. Chromatin IP/PCR reactions were carried out with wild-type and Kin28 mutant yeast strains. Kin28 is the catalytic kinase subunit of basal transcription factor TFIIH. The Kin28 (T17D) allele produces a stable protein with dramatically reduced kinase activity (M. Keogh and S. Buratowski, unpubl.). Immunoprecipitating antibodies are indicated to the left of the autoradiographs. The CTD signal is with monoclonal 8WG16, which recognizes the unphosphorylated CTD, whereas CTD phosphorylated at Ser 5 (CTD-S5-P) is recognized by the monoclonal H14. TFIIE was monitored using a polyclonal antiserum against the small subunit Tfa2.