PROMOTER RECOGNITION IN ARCHAEA IS MEDIATED BY TRANSCRIPTION FACTORS - IDENTIFICATION OF TRANSCRIPTION FACTOR ATFB FROM METHANOCOCCUS-THERMOLITHOTROPHICUS AS ARCHAEAL TATA-BINDING PROTEIN

At least two transcription factors, aTFB and aTFA, are required for ac curate and faithful in vitro transcription of homologous templates in cell-free extracts from the methanogenic Archaeon Methanococcus thermo litho-trophicus. We have recently shown that the function of aTFB can be replaced by eucaryal TATA-binding proteins. Here we demonstrate usi ng template commitment experiments that promoter recognition in an Arc haeon is mediated by transcription factors. The archaeal TATA box was identified as recognition site for binding of aTFB by gel shift analys es. aTFB binds also to the TATA box of adenovirus 2 major late promote r suggesting homology of eucaryal and archaeal TATA boxes. Our analyse s provide evidence for a common molecular mechanism of transcription i nitiation by eucaryal RNA polymerases and archaeal RNA polymerase. The y indicate also an evolutionary homology for aTFB and TBP.