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 Plus annual

Presents the access of premium content as premium feature

Premium Content

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 annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The lac promoter is known to have overlapping, mutually exclusive, binding sites for RNA polymerase. A number of techniques have been used to probe solutions of polymerase and linear lac DNA fragments, including gel electrophoresis binding assays, transcription experiments, and exonuclease III digestions. The data indicate that mixing RNA polymerase with the wild type lac promoter leads to formation of more than one kind of complex; a typical solution contains enzyme in heparin resistant, "open" complexes at the P2 site, while other DNA molecules have polymerase bound in a heparin sensitive, "closed" complex at P1. There may be other rather stable complexes as well. The presence of more than one type of complex has obvious implications for in vitro physical studies of this system. The data suggest that using truncated DNA fragments which eliminate the P2 site may allow isolation and study of P1 closed complexes. Quantitative analysis of the fractions of polymerase found at P1 and P2 implies that P2 can have only a limited effect on lac transcription in the cell.

Solutions of RNA polymerase plus linear wild typeE. eoli lacDNA fragments contain a mixture of stable PI and P2 promoter complexes