FIGURE 1.

Domain architecture and structural alignment of the h/yFACT complexes. The hFACT heterodimeric complex is composed of the hSpt16 (cyan) and SSRP1 (dark green) subunits. Dimerization is accomplished through specific interactions between adjacent DDs in Spt16 and SSRP1/Pob3. The yPob3 (light green) protein is analogous to the SSRP1 protein and combines with ySpt16 and the HMG domain-containing protein Nhp6 to form the yFACT complex. Structural alignments of the h/ySpt16 subunits and SSRP1/Pob3-Nhp6 subunits are based upon previous limited proteolysis experiments and functional analysis of truncated FACT constructs (11, 20, 22, 23).