Finzi Laboratory shows that protein-mediated looping of DNA can organize topological domains that coordinate gene regulation

Supercoiling can alter the form and base pairing of the DNA double helix, and it directly impact protein binding to the DNA. To characterize the extent of constrained DNA supercoiling, 400 base pair, lac repressor protein-secured loops were formed in extensively over- or under-wound DNA, under gentle tension in a magnetic tweezer instrument.  The results show that loop-mediating proteins operating on supercoiled substrates can establish topological domains that may coordinate gene regulation and other DNA transactions across spans in the genome, that are larger than the separation between the binding sites.

The work is described in two recent publications in Nucleic Acids Research, which feature recent Finzi Lab PhD graduate, Yan Yan, as lead author.

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