The binding of SNAPc to the PSE is stabilized not only by cooperative interactions with the Oct-1 POU domain, but also by cooperative interactions with TBP and Brf2 (Hinkley et al., 2003 ; Ma and Hernandez, 2002; Mittal and Hernandez, 1997). Moreover, Brf2, which cannot bind to DNA on its own, recognizes and stabilizes TBP bound to the TATA box (Cabart and Murphy, 2001; Cabart and Murphy, 2002; Ma and Hernandez, 2002). Thus, the U6 transcription initiation complex is stabilized by a complex network of protein-protein and protein-DNA interactions. Nothing is known, however, about how the complex recruits RNA polymerase III.