Nascent RNA structure modulates the transcriptional dynamics of RNA polymerases.
Proc Natl Acad Sci U S A
; 109(23): 8948-53, 2012 Jun 05.
Article
em En
| MEDLINE
| ID: mdl-22615360
ABSTRACT
RNA polymerase pausing represents an important mechanism of transcriptional regulation. In this study, we use a single-molecule transcription assay to investigate the effect of template base-pair composition on pausing by RNA polymerase II and the evolutionarily distinct mitochondrial polymerase Rpo41. For both enzymes, pauses are shorter and less frequent on GC-rich templates. Significantly, incubation with RNase abolishes the template dependence of pausing. A kinetic model, wherein the secondary structure of the nascent RNA poses an energetic barrier to pausing by impeding backtracking along the template, quantitatively predicts the pause densities and durations observed. The energy barriers extracted from the data correlate well with RNA folding energies obtained from cotranscriptional folding simulations. These results reveal that RNA secondary structures provide a cis-acting mechanism by which sequence modulates transcriptional elongation.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
/
Transcrição Gênica
/
RNA Polimerase II
/
RNA Polimerases Dirigidas por DNA
/
RNA
/
Proteínas de Saccharomyces cerevisiae
/
Proteínas Mitocondriais
/
Modelos Biológicos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article