Eukaryotic RNA polymerase II binds to nucleosome cores from transcribed genes.

Purified RNA polymerase II from calf thymus can bind to about 15% of the nucleosome core particles prepared from mouse myeloma cells, forming a discrete complex having a sedimentation coefficient of 18S. These bound nucleosome cores are heavily enriched in transcribed DNA sequences, are deficient in histones H2A and H2B, and undergo a reversible change in structure on RNA polymerase II binding.