In order to get to their target sites, nearly all DNA binding proteins need to use some form of facilitated diffusion—for example, hopping, jumping, sliding and/or intersegmental transfer. Doing so can be made more difficult when nucleosomes are in their way. But is that really the case? Green and coworkers examine two different mismatch repair proteins using single-molecule microscopy and chromatin curtains and find that one can readily bypass the nucleosome by hopping over it while the other slides along until it is stopped in its tracks by the nucleosome. These types of studies can be used to distinguish between these different types of facilitated diffusion along chromatin.
- Jason Gorman
- Aaron J Plys
- Eric C Greene