Abstract:
:The gal operon of Escherichia coli is negatively regulated by repressor binding to bipartite operators separated by 11 helical turns of DNA. Synergistic binding of repressor to separate sites on DNA results in looping, with the intervening DNA as a topologically closed domain containing the two promoters. A closed DNA loop of 11 helical turns, which is in-flexible to torsional changes, disables the promoters either by resisting DNA unwinding needed for open complex formation or by impeding the processive DNA contacts by an RNA polymerase in flux during transcription initiation. Interaction between two proteins bound to different sites on DNA modulating the activity of the intervening segment toward other proteins by allostery may be a common mechanism of regulation in DNA-multiprotein complexes.
journal_name
Proc Natl Acad Sci U S Aauthors
Choy HE,Park SW,Parrack P,Adhya Sdoi
10.1073/pnas.92.16.7327subject
Has Abstractpub_date
1995-08-01 00:00:00pages
7327-31issue
16eissn
0027-8424issn
1091-6490journal_volume
92pub_type
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