Structural dynamics of nucleosomes at single-molecule resolution

The detailed mechanisms of how DNA that is assembled around a histone core can be accessed by DNA-binding proteins for transcription, replication, or repair, remain elusive nearly 40 years after Kornberg's nucleosome model was proposed. Uncovering the structural dynamics of nucleosomes is a crucial step in elucidating the mechanisms regulating genome accessibility. This requires the deconvolution of multiple structural states within an ensemble. Recent advances in single-molecule methods enable unprecedented efficiency in examining subpopulation dynamics. In this review, we summarize studies of nucleosome structure and dynamics from single-molecule approaches and how they advance our understanding of the mechanisms that govern DNA transactions.