FUNCTIONAL INTERACTION OF YEAST AND HUMAN TATA-BINDING PROTEINS WITH AN ARCHAEAL RNA-POLYMERASE AND PROMOTER

TATA boxes are common structural features of eucaryal class II and arc haeal promoters. In addition, a gene encoding a polypeptide with seque nce similarity to eucaryal TATA-binding protein (TBP) has recently bee n detected in Archaea, but its relationship to the archaeal transcript ion factors A (aTFA) and B (aTFB) was unclear. Here, we demonstrate th at yeast and human TBP can substitute for aTPB in a Methanococcus-deri ved archaeal cell-free transcription system. Template-commitment studi es show that eucaryal TBP is stably sequestered at the archaeal promot er and that this interaction is further stabilized in combination with aTFA. Binding studies revealed that recognition of an archaeal promot er by TBP involves specific binding to the TATA box. These findings de monstrate a common function of TBP and aTFB and imply a common evoluti onary origin of eucaryal and archaeal transcriptional machinery.