This suite produced a dynamic range of expression strength, exhibiting a 78 fold change between the lowest expressing promoter, Psca8- and the highest expressing promoter, Psca3-2 when tested within Synechocystis sp. PCC 6803.
It follows that for constant experimental settings the function f(p) is a constant, and the difference with respect to hypocotyl length between the over-expressing line and the wild type is completely captured by the expression strength parameter z.
Were it not for nucleosomes, changing a gene's threshold would simultaneously affect its expression strength.
Second, no significant correlations between expression strength and the firing rate or oscillatory power were detected (Supplementary Fig. 8).
What we've found is that these hidden sites serve primarily to scale up the total gene expression strength.
Synthetic promoters and TFs can provide tremendous advantages over their natural counterparts with regards to transgene expression strength and specificity.
Interestingly, because these sites collectively come into play only after the gene has first been triggered through the exposed sequences, a gene's threshold can be programmed largely independently from its expression strength.
The challenges are the expression strength of chromosomally engineered genes under constitutive promoters is much weaker than the vector engineered genes under inducible promoters.
Using the heat stable β-galactosidase as reporter, the promoter fragment exhibited high expression strength both in Escherichia coli and B. subtilis.
However, a stringent, effective, and convenient-to-use inducible gene expression system that can be used for regulating the gene expression strength in C. acetobutylicum is currently not available.
Once again, an appropriate expression strength of genes made tremendous contribution to the overall yield of the final product.
