Promoter opening (melting) and transcription initiation by RNA polymerase I requires neither nucleotide β, γ hydrolysis norprotein phosphorylation

Abstract

With some bacterial RNA polymerases and In eukaryotic RNA polymerase II, DNA melting during Initiation requires the coupling of energy derived from β, γ hydrolysis of ATP. A detailed analysis of this possible requirement for eukaryotic RNA polymerase I reveals no such requirement. However, in some cases, β, γ non-hydrolyzable derivatives (β, γ Imido or methylene) of nucleotide substrates have been found to significantly Inhibit transcription initiation because of their inefficient use as the first nucleotlde of the transcript. in addition, the results presented here show that protein kinase activity Is not requIred as an integral part of transcription initiation by RNA polymerase I. Prior phosphorylatlon of proteins participating in the process is not ruled out. © 1993 Oxford University Press.