The release element of the yeast polymerase I transcription terminator can function independently of Reb1p.

AUTOR(ES)

Jeong, S W

RESUMO

The Saccharomyces cerevisiae polymerase I (polI) transcription terminator utilizes a DNA-binding protein (Reb1p) as part of a signal that causes the polymerase to pause prior to release from the template. To study the release element of the terminator, independent of the Reb1p pause signal, we have replaced the Reb1p binding site with the binding site for the lac repressor, which acts as a self-contained heterologous pause signal for polI. Release efficiency is maximal when the lac repressor causes polI to pause in exactly the same position that Reb1p would have caused it to pause, suggesting that polI must be precisely positioned for transcript release to occur. Mutational analysis shows that the release element is a region rich in T residues which codes for the extreme 3' end of the transcript and which has no apparent ability to form hairpins when transcribed into RNA. We discuss possible mechanisms whereby this polI release element might function.

Documentos Relacionados

• Transcription termination of RNA polymerase I due to a T-rich element interacting with Reb1p.
• Altered structure of the DNA duplex recognized by yeast transcription factor Reb1p.
• A bipartite DNA-binding domain in yeast Reb1p.
• Saccharomyces cerevisiae RNA Polymerase I Terminates Transcription at the Reb1 Terminator In Vivo
• The REB1 site is an essential component of a terminator for RNA polymerase I in Saccharomyces cerevisiae.