第1163回生物科学セミナー

Single molecule investigations on the structure and dynamics of the nucleosome

Tae-Hee Lee(Department of Chemistry and the Huck Institutes of the Life Sciences The Pennsylvania State University, USA)

2017年07月13日(Thu)    15:00-17:00  理学部3号館 327号室   

The nucleosome is the fundamental packing unit of the eukaryotic genome.
The structure and structural dynamics of the nucleosome are at the core of
gene regulation mechanisms. I will present an overview of our single
molecule investigations on how the nucleosome and its dynamics are altered
by various epigenetic modifications including DNA methylation, histone
acetylation, and histone variations such as H3 to CENP-A and H2A to H2A.Z.
Our study revealed that these chromatin modifications induce changes in the
structure, assembly, and disassembly of nucleosomes that may directly
contribute to their regulatory functions. Our experimental system can also
report real-time dynamics of transcription elongation, based on which we
elucidated the role of a highly conserved and essential elongation factor
Spt4/5. These studies clearly demonstrate that single molecule methods
provide powerful tools to complement ensemble-averaged measurements and
static structures in chromatin research.