You are studying a human gene, and try to express the protein in E. coli bacterial cells. To do this, you use lab cloning techniques to create an expression vector - a circular piece of DNA (plasmid) which can replicate within E. coli, and which contains an appropriate E. coli promoter sequence before the human protein sequence. Note that the sequence used is the final mRNA protein coding sequence, with all introns removed. You can detect that some of the protein is produced, but it's a very small amount. Luckily you included a positive control, which uses the same expression vector, and find that the control E. coli protein is expressed to high levels under the same conditions. A colleague suggests that you transform your same expression vector into a 'humanized' strain of E. coli that is optimized for the expression of human recombinant proteins (this is a real thing!). You do this and see protein expression – woohoo! If the genetic code is universal, why might a human gene be poorly translated in wild-type E. coli but could be better translated in the optimized strain? Propose a specific type of change which was made in the modified E. coli to account for the difference?
Bacterial Genomics
The study of the morphological, physiological, and evolutionary aspects of the bacterial genome is referred to as bacterial genomics. This subdisciplinary field aids in understanding how genes are assembled into genomes. Further, bacterial or microbial genomics has helped researchers in understanding the pathogenicity of bacteria and other microbes.
Transformation Experiment in Bacteria
In the discovery of genetic material, the experiment conducted by Frederick Griffith on Streptococcus pneumonia proved to be a stepping stone.
Plasmids and Vectors
The DNA molecule that exists in a circular shape and is smaller in size which is capable of its replication is called Plasmids. In other words, it is called extra-chromosomal plasmid DNA. Vectors are the molecule which is capable of carrying genetic material which can be transferred into another cell and further carry out replication and expression. Plasmids can act as vectors.
You are studying a human gene, and try to express the protein in E. coli bacterial cells. To do this, you use lab cloning techniques to create an expression vector - a circular piece of DNA (plasmid) which can replicate within E. coli, and which contains an appropriate E. coli promoter sequence before the human protein sequence. Note that the sequence used is the final mRNA protein coding sequence, with all introns removed.
You can detect that some of the protein is produced, but it's a very small amount. Luckily you included a positive control, which uses the same expression vector, and find that the control E. coli protein is expressed to high levels under the same conditions. A colleague suggests that you transform your same expression vector into a 'humanized' strain of E. coli that is optimized for the expression of human recombinant proteins (this is a real thing!). You do this and see protein expression – woohoo!
If the genetic code is universal, why might a human gene be poorly translated in wild-type E. coli but could be better translated in the optimized strain? Propose a specific type of change which was made in the modified E. coli to account for the difference?
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