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Updated: Aug 9, 2026

High-throughput Purification of Affinity-tagged Recombinant Proteins
Published on: August 26, 2012
The RNA polymerase I transcription machinery
Jackie Russell1, Joost C B M Zomerdijk
1Division of Gene Regulation and Expression, School of Life Sciences, University of Dundee, Wellcome Trust Biocentre, Dundee DD1 5EH, UK.
Abstract:
The rRNAs constitute the catalytic and structural components of the ribosome, the protein synthesis machinery of cells. The level of rRNA synthesis, mediated by Pol I (RNA polymerase I), therefore has a major impact on the life and destiny of a cell. In order to elucidate how cells achieve the stringent control of Pol I transcription, matching the supply of rRNA to demand under different cellular growth conditions, it is essential to understand the components and mechanics of the Pol I transcription machinery. In this review, we discuss: (i) the molecular composition and functions of the Pol I enzyme complex and the two main Pol I transcription factors, SL1 (selectivity factor 1) and UBF (upstream binding factor); (ii) the interplay between these factors during pre-initiation complex formation at the rDNA promoter in mammalian cells; and (iii) the cellular control of the Pol I transcription machinery.
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