Fig. 5.5.

Structure and function of TFIIH. a Schematic of TFIIH architecture. Main enzymatic subunits are shown in color (XPD and XPB, SF2-family DNA-dependent ATPases; CDK7, Cyclin-dependent kinase). Core and CAK subcomplexes are indicated. b Model for the activity of the TFIIH subunit XPB during promoter opening; depiction based on the structures in (He et al. 2016). c Cryo-EM reconstruction of the human Pol II-PIC (He et al. 2016) with fitted coordinate models. TFIIH subunits are highlighted in color. d, e Relocalization of the CAK kinase-cyclin module in the Mediator-bound Pol II-PIC (Schilbach et al. 2017): The cryo-EM volume corresponding to the CAK in the Mediator-containing PIC is shown in orange. The presumed location of the CAK in the absence of Mediator is indicated by an orange ellipse. f Structure of the TFIIH core complex with bound MAT1 (Greber et al. 2019). g Interactions of p62 with the ATP-and DNA-binding sites of XPD. h Mapping of human disease mutations onto the structure of TFIIH (Cleaver et al. 1999; Greber et al. 2019)