English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Significance Low levels of λ repressor (CI) can autoenhance expression and lysogeny (quiescence) of bacteriophage λ infection. However, additional CI mediates an autorepressive DNA loop. Supercoiling catalyzes looping in unstretched plasmids, but whether supercoiling catalyzes looping under tension, and whether thecI promoter within the loop becomes superhelically isolated were investigated. CI efficiently partitioned plasmids into topological domains and formed barriers to the passage of supercoiling from one into another. Furthermore, in single DNA molecules twisted with magnetic tweezers, CI-mediated DNA loops confined as much as −15% to +11% supercoiling. Finally, under gentle tensions likely to occur in vivo, supercoiling was essential for looping. CI may exploit supercoil-driven looping events to regulate the lysogenic/lytic switch.

DNA supercoiling: A regulatory signal for the λ repressor