New Model for the Yeast RNA Polymerase I Transcription Cycle

AUTOR(ES)

Aprikian, Pavel

FONTE

American Society for Microbiology

RESUMO

Using an immobilized template assay, we observed two steps in assembly of the yeast RNA polymerase I (Pol I) preinitiation complex: stable binding of upstream activating factor (UAF) followed by recruitment of Pol I-Rrn3p and core factor (CF). Pol I is required for stable association of CF with the promoter and can be recruited in the absence of Rrn3p. Upon transcription initiation, Pol I-Rrn3p and CF dissociate from the promoter while UAF remains behind. These findings support a novel model in which the Pol I basal machinery cycles on and off the promoter with each round of transcription. This model accounts for previous observations that rRNA synthesis may be controlled by regulating both promoter accessibility and polymerase activity.

Documentos Relacionados

• Termination of transcription by yeast RNA polymerase I.
• Histones are required for transcription of yeast rRNA genes by RNA polymerase I
• Transcription-coupled repair in RNA polymerase I-transcribed genes of yeast
• In Vivo Binding and Hierarchy of Assembly of the Yeast RNA Polymerase I Transcription Factors
• TATA Binding Protein Can Stimulate Core-Directed Transcription by Yeast RNA Polymerase I