Bacteria gene expression

Many proteins that switch off or on gene expression in bacteria are dimeric molecules, and the DNA sequences that they specifically recognize are palindromic at their ends. The twofold symmetry of the protein is therefore matched by twofold symmetry at the ends of the recognition sequence. 

Good L., Nielsen P.E. Antisense inhibition of gene expression in bacteria by PNA targeted to mRNA. Nature Biotech-nol. 1998 16 355-358. 

In a normally growing culture of lysogenic bacteria, the majority of bacteria manage to keep their prophages in a dormant state. In a very small minority of cells, however, the prophage genes express themselves. This results in the multiplieation of the virus, lysis of the cells and liberation of infectious particles into the medium. 

Ahmad D, R Masse, M Sylvestre (1990) Cloning, physical mapping and expression in Pseudomonas putida of 4-chlorobiphenyl transformation genes from Pseudomonas testosteroni strain B-356 and their homology to the genomic DNA from other PCB-degrading bacteria. Gene 86 53-61. 

Keasling, J.D. (1999) Gene-expression tools for the metabolic engineering of bacteria. Trends in Biotechnology, 17, 452-460. 

The performance of a biotreatment system ultimately depends on optimization of the activity of microbes and the ability to control the process parameters of the treatment system [157]. In this respect, the ability to monitor gene copy numbers and gene expression is highly useful for real time optimization of the efficiency of a biotreatment system. Advanced molecular techniques as well as low cost methods (e.g., antibody detection of enzymes based on color reaction strips fluorescence i.e., GFP marked organisms with UV light detection) can also be applied to monitor the microbial community structure, persistence of the added bacteria, and their interactions with indigenous populations. 

One of the main applications of GFP is as reporter gene. GFP has been expressed in a variety of organisms, including animals [257], plants [258], bacteria [259], and viruses [260], for monitoring gene expression. The attractiveness unique to GFP as a reporter allows nondestructive in vivo fluorescence visualiza-... 

The Lac operon (Figure 3.8, described in Esherichia coli bacteria by Jacob and Monod), illustrates how gene expression can be switched on or off according to sudden changes in environmental conditions. Glucose (a monosaccharide) is the preferred... 

If the end goal of cloning is to have a cloned gene expressed in a cell, the entire coding sequence must be doned intact. Furthermore, if a cloned eukaryotic gene is to be expressed in bacteria (to make recombinant proteins), the gene must not contain introns, which could not be processed in a prokaryotic cell. In these cases it is more convenient to done cDNA rather than DNA restriction fragments. 

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