FIGURE 2.

Structural catalog of the individual domains in FACT with respect to their location in the overall architecture of the complex. Upper panel, the Spt16 subunit of FACT is shown in blue with the NTD displayed as a ribbon diagram from the crystal structure of the ySpt16 NTD (22). The structure reveals an aminopeptidase-like peptide-binding fold suitable for interaction with histone tails. The structures of the remaining domains within h/ySpt16 are presently unknown. Lower panel, the known structures of the Pob3 subunit of FACT are displayed as respective domains in the Pob3 molecule. The NTD/DD and MD present similar PH ligand-binding domains (NTD/DD, single; and MD, double) (Protein Data Bank code 3F5R) (19). The structure of Nhp6a in complex with DNA is also shown (green) and is aligned with the HMG domain from SSRP1 (orange) (29, 30). Structures for remaining SSRP1 domains analogous to those shown for Pob3 are unavailable.