Quantitation of the DNA tethering effect in long-range DNA looping in vivo and in vitro using the Lac and λ repressors.

ABSTRACT: Efficient and specific interactions between proteins bound to the same DNA molecule can be dependent on the length of the DNA tether that connects them. Measurement of the strength of this DNA tethering effect has been largely confined to short separations between sites, and it is not clear how it contributes to long-range DNA looping interactions, such as occur over separations of tens to hundreds of kilobase pairs in vivo. Here, gene regulation experiments using the LacI and λ CI repressors, combined with mathematical modeling, were used to quantitate DNA tethering inside Escherichia coli cells over the 250- to 10,000-bp range. Although LacI and CI loop DNA in distinct ways, measurements of the tethering effect were very similar for both proteins. Tethering strength decreased with increa

SUBMITTER: Priest DG 

PROVIDER: S-EPMC3890862 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature