Interplay of the Tfb1 pleckstrin homology domain with Rad2 and Rad4 in transcription coupled and global genomic nucleotide excision repair.

Transcription-coupled repair (TCR) and global genomic repair (GGR) are two subpathways of nucleotide excision repair (NER). The TFIIH subunit Tfb1 contains a Pleckstrin homology domain (PHD), which was shown to interact with one PHD-binding segment (PB) of Rad4 and two PHD-binding segments (PB1 and PB2) of Rad2 in vitro. Whether and how the different Rad2 and Rad4 PBs interact with the same Tfb1 PHD, and whether and how they affect TCR and GGR within the cell remain mysterious.