I have a question about using arabinose inducible promoter on plasmid inside e coli. If araC is present in the genome such as e coli, do I still need araC before pBAD promoter on the plasmid? I assume the genome expression of araC should be OK to control pBAD promoter. Thank you in advance!
You might not get tight enough control since there is only one chromosomal copy of araC while there are multipe copies of the promoter on the plasmid and therefore depedening on the plasmid copy number you might titrate away the araC causing messy results since the araC can act both as a suppressor and activator.
There is many other factors to controlling gene expression. Take a look.
Guzman LM, Belin D, Carson MJ, Beckwith J. Tight regulation, modulation, and high-level expression by vectors containing the arabinose PBAD promoter. J Bacteriol. Jul 1995; 177(14): 4121–4130.
Regards.
I agree with Hanna Alalam that you will likely not have sufficient AraC molecules present in the cell to control a high copy number plasmid. So in addition to some leaky expression you will likely fail to obtain high levels of expression due to inability to fully induce all plasmid copies.
- Badges
- Science topic