Role for the amini-terminal region of human TBP in U6 snRNA transcription

Basal transcriptional from the human RNA apolymerase III U6 promoter depends on a TATA box that recruits the TATA box-binding protein (TBP) and a proximal sequence element that recruits the small nuclear RNA (snRNA)- activating protein complex (SNAP). TBP consists of a conserved carboxyl- terminal domain that performs all known function of the protein and a conconserved amino-terminal region of unknown function. Here, the amino- terminals region is shown to down-regulate binding of TBP to the U6 TATA box, mediate cooperative binding with SNAP to the U6 promoter, and enhance U6 transcription.