Yeast chromatin reconstitution system using purified yeast core histones and yeast nucleosome assembly protein-1.

Transcription regulation in the cell occurs in the context of chromatin. It follows that a thorough investigation of the mechanism of transcription regulation must take into account the role of chromatin structure. Through classical and molecular genetic experiments in yeast, great strides have been made in understanding the role of chromatin in eukaryotic gene regulation. To achieve a more detailed understanding of the biochemical mechanism of transcription regulation, a yeast chromatin reconstitution system is needed. This need drove us to develop a yeast core histone purification procedure for the reconstitution of these histones into chromatin templates using components wholly derived from yeast. We have purified native yeast core histones in milligram quantities and we have shown these histones to be competent for reconstitution of chromatin templates using yeast nucleosome assembly protein-1. This accomplishment sets the stage for studies using the full power of yeast as an experimental organism to investigate the role of chromatin in transcription regulation.