Synergistic action of RNA polymerases in overcoming the nucleosomal barrier.
Nat Struct Mol Biol
; 17(6): 745-52, 2010 Jun.
Article
em En
| MEDLINE
| ID: mdl-20453861
ABSTRACT
During gene expression, RNA polymerase (RNAP) encounters a major barrier at a nucleosome and yet must access the nucleosomal DNA. Previous in vivo evidence has suggested that multiple RNAPs might increase transcription efficiency through nucleosomes. Here we have quantitatively investigated this hypothesis using Escherichia coli RNAP as a model system by directly monitoring its location on the DNA via a single-molecule DNA-unzipping technique. When an RNAP encountered a nucleosome, it paused with a distinctive 10-base pair periodicity and backtracked by approximately 10-15 base pairs. When two RNAPs elongate in close proximity, the trailing RNAP apparently assists in the leading RNAP's elongation, reducing its backtracking and enhancing its transcription through a nucleosome by a factor of 5. Taken together, our data indicate that histone-DNA interactions dictate RNAP pausing behavior, and alleviation of nucleosome-induced backtracking by multiple polymerases may prove to be a mechanism for overcoming the nucleosomal barrier in vivo.
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
3_ND
Base de dados:
MEDLINE
Assunto principal:
RNA Polimerases Dirigidas por DNA
/
Nucleossomos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Nat Struct Mol Biol
Ano de publicação:
2010
Tipo de documento:
Article