Yeast DNA repair protein RAD23 promotes complex formation between transcription factor TFIIH and DNA damage recognition factor RAD14.

In Saccharomyces cerevisiae, the multisubunit RNA polymerase II general transcription factor TFIIH is indispensable for transcription initiation and some of its subunits are known to be required for nucleotide excision repair (NER) of DNA damaged by ultraviolet light. RAD3, a subunit of TFIIH, binds UV-damaged DNA in an ATP-dependent manner. It has, however, remained unclear how TFIIH is assembled with the other damage recognition component RAD14. Here, we demonstrate a higher order complex consisting of TFIIH, RAD14, and another NER protein RAD23, and complex formation between TFIIH and RAD14 is facilitated by the RAD23 protein.