Showing papers by "Alan P. Wolffe published in 1990"
TL;DR: The application of the hydroxyl radical footprinting technique is described to examine the histone-DNA interactions of a nucleosome that includes part of the 5S ribosomal RNA gene of Xenopus borealis and establishes that two distinct regions of DNA with different helical periodicities exist within the nucleosomes.
Abstract: We describe the application of the hydroxyl radical footprinting technique to examine the histone-DNA interactions of a nucleosome that includes part of the 5S ribosomal RNA gene of Xenopus borealis. We establish that two distinct regions of DNA with different helical periodicities exist within the nucleosome and demonstrate a change in the helical periodicity of this DNA upon nucleosome formation. In particular, we find that on average the helical periodicity of DNA in this nucleosome is 10.18 +/- 0.05 base pairs per turn. The same DNA, when bound to a calcium phosphate surface, has a periodicity of 10.49 +/- 0.05 base pairs per turn, similar to that of random sequence DNA. Modulations in minor groove width within the naked DNA detected by the hydroxyl radical are maintained and exaggerated in nucleosomal DNA. These features correlate with regions in the DNA previously suggested to be important for nucleosome positioning.
487 citations
Journal Article•
TL;DR: Progress in understanding how genes are transcribed in a chromatin environment provides important insights into the means by which specific protein-DNA interactions occur within the nucleus.
Abstract: Our current knowledge of chromatin structure raises the major issue of the accessibility of DNA to the proteins involved in macromolecular processes such as replication, recombination, and transcription. Recent genetic and biochemical analyses have both proven that chromatin structure plays a role in specifically repressing the initiation of transcription of several genes and suggested how this repression might be overcome in vivo. Such progress in understanding how genes are transcribed in a chromatin environment provides us with important insights into the means by which specific protein-DNA interactions occur within the nucleus.
31 citations
TL;DR: In this article, protein-DNA interactions associated with the transcription complex of a Xenopus somatic 5 S RNA gene under efficient in vitro transcription conditions were defined, showing that the sequence 5' and 3' of the internal control region of the 5S RNA gene are essential for transcription by RNA polymerase III in vitro.
23 citations