DNA supercoiling: a regulatory signal for the λ repressor.

ABSTRACT: Topoisomerases, polymerases, and the chirality introduced by the binding of histones or nucleoid-associated proteins affect DNA supercoiling in vivo. However, supercoiling is not just a by-product of DNA metabolism. Supercoiling is an indicator of cell health, it modifies the accessibility of chromatin, and coordinates the transcription of genes. This suggests that regulatory, protein-mediated loops in DNA may sense supercoiling of the genome in which they are embedded. The λ repressor (CI) maintains the quiescent (lysogenic) transcriptome of bacteriophage λ in infected Escherichia coli. CI-mediated looping prevents overexpression of the repressor protein to preserve sensitivity to conditions that trigger virulence (lysis). Experiments were performed to assess how well the CI-mediated DNA

SUBMITTER: Ding Y 

PROVIDER: S-EPMC4217475 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature