Extended Data Fig. 5: Structural insights on TAF1 interaction hotspots.

a, Summary of TAF1 intracrosslinks from crosslinking-mass spectrometry metanalysis derived from three independent studies^10,18,19. Only crosslinks reported in at least two independent datasets are shown. b., Interprotein crosslinks of TAF1 Lys249 are mapped on the AlphaFold (AF) model of the TAF1_1-300/TAF11_50-211/TAF13/TBP_150-339 complex. c, Mapping of interprotein crosslinks between TAF1 and TAF6/TAF8 in the AF model of TAF1_300-550/TAF6^HEAT/TAF6^HEAT/TAF8_128-218 subcomplex. d, Cryo-EM structure of TAF1 T6BMs in complex with TAF6 HEAT domains and TAF8 (PDB: 7EGH). The rest of C lobe was removed for clarity. e, The AF model described in (c) is shown with TAF1 colored according to pLDDT confidence score and in the same orientation of the experimental structure shown in (d). f, 180 degrees rotation of the model shown in (e). g, Interface map of the model shown in (e). The size of each node is proportional to the protein surface area. The values correspond to the buried solvent- accessible surface area between the two connected nodes. Only interfaces with a buried surface area >300 Ų are shown. TAF1 bridges the two TAF6 HEAT domain copies in the complex. h, Equivalent surface patches contacted by TAF1 T6BMs on each of the two copies of TAF6 HEAT domains are highlighted with the same color. In each view the second HEAT domain copy is not shown for clarity. Distinct portions of TAF1 bind to equivalent surfaces on the two copies of TAF6. The representation is based on the model shown in (e). i, Interprotein crosslinks of TAF1 are mapped on TFIID C lobe Cryo-EM structure (PDB: 7EGH). For all panels, crosslinks compatible with crosslinker length (Cα-Cα distance < 26 Å) are displayed as yellow pseudobonds. Red pseudobonds correspond to crosslinks that exceed that distance.