Expression systems in eukaryotes and prokaryotes
Answers
Expression systems are used for the production of protein from recombinant DNA molecules (see Recombinant Proteins). They are of widespread use in industry, health care, and scientific research because of their flexibility and ability to achieve production levels exceeding those of the native source of the protein. An expression system consists of a vector carrying the gene encoding the protein of interest, along with the sequences necessary for transcription of the DNA into messenger RNA and translation of the mRNA into protein, plus a host providing the enzymatic machinery for carrying out these processes. In a homologous expression system, the gene to be expressed derives from the same species as the host whereas, in a heterologous expression system, the gene to be expressed and the host are of different origin.