A. Structural overview of human TFIIH. XPB and the CAK module are colored in fuchsia and purple, respectively (PDB ID 7ENC)[4]. The positions of CDK7, MAT1, and XPD are indicated.
B. DNA translocation by XPB facilitates promoter opening. XPB ATPase lobe 1 in the apo (PDB ID 7NVW, pink and green)[17] and ADP·BeF3 bound states (PDB ID 7NVV, fuchsia and blue)[17] are aligned. Binding of ADP·BeF3 induces closure of the XPB ATPase and propagation of the local DNA twist upstream.