Events during Initiation of Archaeal Transcription: Open Complex Formation and DNA-Protein Interactions

Abstract

Transcription in Archaea is initiated by association of a TATA box binding protein (TBP) with a TATA box. This interaction is stabilized by the binding of the transcription factor IIB (TFIIB) orthologue TFB. We show here that the RNA polymerase of the archaeon Methanococcus , in contrast to polymerase II, does not require hydrolysis of the β-γ bond of ATP for initiation of transcription and open complex formation on linearized DNA. Permanganate probing revealed that the archaeal open complex spanned at least the DNA region from −11 to −1 at a tRNA ^Val promoter. The Methanococcus TBP-TFB promoter complex protected the DNA region from −40 to −14 on the noncoding DNA strand and the DNA segment from −36 to −17 on the coding DNA strand from DNase I digestion. This DNase I footprint was extended only to the downstream end by the addition of the RNA polymerase to position +17 on the noncoding strand and to position +13 on the coding DNA strand.