Figure 2. A TAF1-TAF7 subcomplex forms a downstream promoter-binding module.

a, Docking of the human TAF1-TAF7 complex (PDB code 4RGW)²⁴ into the locally-refined lobe C density. Promoter is colored as in Fig. 1. The location of the segmented density in the overall map is highlighted in the lower-left. b, Closeup view of the TAF1 WH domain (dark grey) bound to promoter DNA. c, The TAF1 WH domain with residues colored according to conservation (Extended Data fig. 4a). Conserved positively-charged residues that appear involved in DNA binding are shown as ball-and-sticks. d, Predicted 3D structure for the TAF1 segment spanning residues 1013–1057, docked into the protein density bound to the Inr promoter element. The predicted unstructured linker regions (993–1013 and 1056–1075) are represented as dashed lines. e, Putative interaction between TBP and the TAND of TAF1 within the canonical state of TFIID. The low-resolution reconstruction of TFIID in the canonical state³³ is shown in mesh, superimposed on the new structure of promoter-bound TFIID. The domain organization of human TAF1 is shown at the top (the DUF3591 domain has been localized in this study).