Figure 2.

Immunolabelling of TAF1 domains. (A) Schematic representation of the structural and functional features of yTAF1. In (B–E), the stars below the inset indicate the portion of TAF1 recognized by the antibodies used. (B) Average images of TFIID molecules specifically labelled with a pAb raised against full-length TAF1 (Ab1-TAF1). Several classes of images differing by the position of the antibody-binding site were found and likely correspond to distinct epitopes (left panel). The density difference maps between the various labelled classes and the unlabelled TFIID were aggregated into a single diagram for clarity (upper right panel). The lower right panel summarized the results obtained with Ab1-TAF1 by mapping the labelled sites on the previously obtained 3-D model of TFIID (Leurent et al, 2002). (C) Average images of TFIID molecules specifically labelled with a pAb raised against the first 100 amino acids of TAF1 (Ab2-TAF1) are depicted in the left panel. The aggregated density difference maps are shown in the right panel and indicate that lobe C is labelled in different regions. (D) Average image of TFIID molecules HA-tagged on the N-terminus of TAF1 and labelled with an anti-HA antibody (Ab3-TAF1). The difference map (right panel) indicates that a single site is labelled in lobe C_II. (E) Average image of TFIID molecules HA-tagged on the C-terminus of TAF1 and labelled with an anti-HA antibody (Ab4-TAF1). The difference map (right panel) indicates that a single site is labelled in lobe A.