ISWI-family enzymes remodel chromatin (the packaged state of DNA) by sliding nucleosomes along DNA. Nucleosomes are the fundamental repeating units of chromatin, and the mechanism by which remodeling enzymes can shift the position of nucleosomes on the DNA remains unclear. We have applied single-molecule fluorescence imaging approaches to visualize nucleosome sliding by ISWI-family remodelers in real-time. They translocate nucleosomes with a conserved stepping pattern that is maintained by the catalytic subunit of the remodelers. Our results suggest a new model for nucleosome remodeling: translocation proceeds in well-defined multi-bp entry steps and 1 bp exit steps and DNA translocation to the exit side precedes any DNA movement on the entry side.


Friday, September 27, 2013, 12:00. Seminar Room

Hosted by Prof. Melike Lakadamyali