AEM
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jensen, P. R.
Right arrow Articles by Hammer, K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jensen, P. R.
Right arrow Articles by Hammer, K.
Agricola
Right arrow Articles by Jensen, P. R.
Right arrow Articles by Hammer, K.

 Previous Article  |  Next Article 

Appl Environ Microbiol, January 1998, p. 82-87, Vol. 64, No. 1
0099-2240/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

The Sequence of Spacers between the Consensus Sequences Modulates the Strength of Prokaryotic Promoters

Peter Ruhdal Jensen* and Karin Hammer

Department of Microbiology, Technical University of Denmark, DK-2800 Lyngby, Denmark

Received 7 July 1997/Accepted 21 October 1997

We constructed a library of synthetic promoters for Lactococcus lactis in which the known consensus sequences were kept constant while the sequences of the separating spacers were randomized. The library consists of 38 promoters which differ in strength from 0.3 up to more than 2,000 relative units, the latter among the strongest promoters known for this organism. The ranking of the promoter activities was somewhat different when assayed in Escherichia coli, but the promoters are efficient for modulating gene expression in this bacterium as well. DNA sequencing revealed that the weaker promoters (which had activities below 5 relative units) all had changes either in the consensus sequences or in the length of the spacer between the -35 and -10 sequences. The promoters in which those features were conserved had activities from 5 to 2,050 U, which shows that by randomizing the spacers, at least a 400-fold change in activity can be obtained. Interestingly, the entire range of promoter activities is covered in small steps of activity increase, which makes these promoters very suitable for quantitative physiological studies and for fine-tuning of gene expression in industrial bioreactors and cell factories.

* Corresponding author. Mailing address: Department of Microbiology, Technical University of Denmark, Building 301, DK-2800 Lyngby, Denmark. Phone: 45 45252510. Fax: 45 45932809. E-mail: prj{at}im.dtu.dk.




This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Microbiol. Mol. Biol. Rev. Eukaryot. Cell All ASM Journals

Copyright © 1998 by the American Society for Microbiology. All rights reserved.