RNA polymerase II elongation through chromatin

The machinery that transcribes protein-coding genes in eukaryotic cells mus t contend with repressive chromatin structures in order to find its target DNA sequences. Diverse arrays of proteins modify the structure of chromatin at gene promoters to help transcriptional regulatory proteins access their DNA recognition sites. The way in which disruption of chromatin structure at a promoter is transmitted through a whole gene has not been defined. Rec ent breakthroughs suggest that the passage of an RNA polymerase through a g ene is coupled to mechanisms that propagate the breakdown of chromatin.