Visualization of RNA polymerase II ternary transcription complexes formed in vitro on a Xenopus laevis vitellogenin gene.
AUTOR(ES)
ten Heggeler, B
RESUMO
Stable ternary transcription complexes assembled in vitro, using a HeLa whole-cell extract, have been isolated and visualized by electron microscopy. The formation of these stable complexes on the DNA fragment used as template, the 5' end region of the Xenopus laevis vitellogenin gene B2, depends on factors present in the whole-cell extract, RNA polymerase II and at least two nucleotides. Interestingly, bending in the DNA fragment was frequently observed at the binding site of RNA polymerase II. Dinucleotides that can prime initiation within a short sequence of approximately 10 contiguous nucleotides centered around the initiation site used in vivo, also favour the formation of stable complexes. In addition, pre-initiation complexes were isolated and it was shown that factors in the extract involved in their formation are more abundant than the RNA polymerase II molecules available for binding. The possible implication of this observation relative to the in vivo situation is discussed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=554496Documentos Relacionados
- RNA polymerase II ternary transcription complexes generated in vitro.
- Vitellogenin B2 gene in Xenopus laevis: isolation, in vitro transcription and relation to other vitellogenin genes.
- Eukaryotic ternary transcription complexes: transcription complexes of RNA polymerase II are associated with histone-containing, nucleosome-like particles in vivo.
- Electron microscopic visualization of protein-DNA interactions at the estrogen responsive element and in the first intron of the Xenopus laevis vitellogenin gene.
- Activation of vitellogenin gene transcription is a direct response to estrogen in Xenopus laevis liver.