Histones H2A/H2B inhibit the interaction of transcription factor IIIA with the Xenopus borealis somatic 5S RNA gene in a nucleosome.
AUTOR(ES)
Hayes, J J
RESUMO
A Xenopus borealis somatic 5S RNA gene was assembled with either the complete octamer of histones, (H2A/H2B/H3/H4)2, or the (H3/H4)2 tetramer of histones that comprises the central protein kernel of the nucleosome. Gel-mobility shifts, DNase I protection, and immunoblotting assays demonstrate that the class III transcription factor IIIA (TFIIIA) readily interacts with 5S DNA associated with the tetramer but that little or no binding is detected when 5S DNA is associated with the full octamer of histones. Thus, the presence of histones H2A and H2B in the 5S nucleosome significantly inhibits the interaction of TFIIIA with its cognate binding site within the 5S RNA gene. We propose that either the depletion of histones H2A and H2B from preexisting nucleosomes or the staged assembly of chromatin after replication in which a tetramer of histones H3/H4 associates with DNA before histones H2A/H2B will facilitate the binding of transcription factors to their cognate DNA sequences.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=48422Documentos Relacionados
- Preferential and asymmetric interaction of linker histones with 5S DNA in the nucleosome.
- Transition mutations within the Xenopus borealis somatic 5S RNA gene can have independent effects on transcription and TFIIIA binding.
- Displacement of Xenopus transcription factor IIIA from a 5S rRNA gene by a transcribing RNA polymerase.
- TFIIIA binds to different domains of 5S RNA and the Xenopus borealis 5S RNA gene.
- Defining the binding site of Xenopus transcription factor IIIA on 5S RNA using truncated and chimeric 5S RNA molecules.