Abstract
A library of synthetic promoters for Lactococcus lactis was
constructed, 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 relative units, and up to more than 2000
relative units, which is among the strongest promoters known for
this organism. The ranking of the promoter activities was somewhat
different when assayed in E. coli, but the promoters are efficient
for modulating gene expression in this bacteria as well. DNA
sequencing revealed that the weaker promoters (which had
activities below 5 relative units) all had either changes 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 2050 units, 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
bio-reactors and cell factories.
| Original language | English |
|---|---|
| Journal | Applied and Environemental Microbiology |
| Volume | 64 |
| Issue number | 1 |
| Pages (from-to) | 82-87 |
| Publication status | Published - 1998 |