Abstract
The P1 promoter of the galactose operon in Escherichia coli is one of the best studied examples of 'extended -10' promoters. Recognition of the P1 promoter does not require specific contacts between RNA polymerase and its poor -35 element. To investigate whether specific recognition of the -35 element would affect the regulation of P1 by GalR, we mutagenized the -35 element of P1, isolated variants of the -35 element and studied the regulation of the mutant promoters by in vitro transcription assays and by mathematical modeling. The results show that the GalR-mediated DNA loop is less efficient in repressing P1 transcription when RNA polymerase binds to the -10 and -35 elements concomitantly. Our results suggest that promoters that lack specific -35 element recognition allow decoupling of local chromosome structure from transcription initiation.
Originalsprog | Engelsk |
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Tidsskrift | Nucleic Acids Research |
Vol/bind | 40 |
Udgave nummer | 20 |
Sider (fra-til) | 10064-10072 |
Antal sider | 8 |
ISSN | 0305-1048 |
DOI | |
Status | Udgivet - 1 nov. 2012 |