Production of Protein from Cloned Genes
2 Production of Protein from Cloned Genes
Now that we have covered the basic techniques involved in gene cloning and DNA analysis and examined how these techniques are used in research, we can move on to consider how recombinant DNA technology is being applied in biotechnology. This is not a new subject, although biotechnology has received far more attention during recent years than it ever has in the past. Biotechnology can be defined as the use of biological processes in industry and technology.
2.1 Overview of Gene Expression
For practical applications it is essential that systems be available in which the cloned genes can be expressed. Organisms have complex regulatory systems, and many genes are not expressed all of the time. One of the major goals of genetic engineering is the development of vectors in which high levels of gene expression can occur. An expression vector is a vector, which not only can be used to clone the desired gene but also contains the necessary regulatory sequences so that expression of the gene is kept under control of the genetic engineer. Some of the elements involved in gene expression are summarized in the Figure 2.1.
DNA Anti-leader Coding sequence Anti-trailer
TAC ACT Promoter Operator Terminator Shine-Delgarno sequence Transcription
mRNA AUG UGA
Leader (5’-UTR) Trailer (3’-UTR)
Translation
Protein
Now that we have covered the basic techniques involved in gene cloning and DNA analysis and examined how these techniques are used in research, we can move on to consider how recombinant DNA technology is being applied in biotechnology. This is not a new subject, although biotechnology has received far more attention during recent years than it ever has in the past. Biotechnology can be defined as the use of biological processes in industry and technology.
2.1 Overview of Gene Expression
For practical applications it is essential that systems be available in which the cloned genes can be expressed. Organisms have complex regulatory systems, and many genes are not expressed all of the time. One of the major goals of genetic engineering is the development of vectors in which high levels of gene expression can occur. An expression vector is a vector, which not only can be used to clone the desired gene but also contains the necessary regulatory sequences so that expression of the gene is kept under control of the genetic engineer. Some of the elements involved in gene expression are summarized in the Figure 2.1.
DNA Anti-leader Coding sequence Anti-trailer
TAC ACT Promoter Operator Terminator Shine-Delgarno sequence Transcription
mRNA AUG UGA
Leader (5’-UTR) Trailer (3’-UTR)
Translation
Protein
References: 1. Gene Cloning and DNA Analysis: An Introduction, Sixth Edition by Brown TA. 2010. Blackwell Science Ltd., Oxford. 2. Genetics: Analysis of Genes and Genomes, Sixth Edition by Daniel L Hartl and Elizabeth W Jones. 2005. Jones & Bartlett Publishers Inc., Boston. 3. Molecular Biotechnology: Principles and Applications of Recombinant DNA, Fourth Edition by Bernard R Glick, Jack J Pasternak and Cheryl L Patten. 2010. ASM Press, American Society for Microbiology, Washington DC. ----------------------- RNA polymerase binding site Repressor binding site