Heterologous host

There is a broad diversity of heterologous hosts for gene expression, and there is no best or universal host which is suitable for the production of all possible proteins. Nevertheless, many proteins can be expressed cheaply and successfully in Escherichia coli, which is still the most preferred host for heterologous production of proteins without posttranslational modifications. 

Galm, U. and Shen, B. (2006) Expression of biosynthetic gene clusters in heterologous hosts for natural product production and combinatorial biosynthesis. Expert Opinion on Drug Discovery, 1, 409. 

Metabolic Engineering for Overproduction of 6dEB in Heterologous Hosts... 

Notable progress has been made on the production of 6dEB in engineered E. coli. E. coli has several advantages as a heterologous host, such as its relatively fast growth rate, the... 

The next step was identification and isolation of DNA fragments encoding the biocatalyst. The same procedure can be applied to any active microorganism. DNA plasmid (Plasmid pTOXI-1 and Plasmid pTOXI-2) and vectors (four different nucleic acid sequences were included, namely SEQ ID No. 1 to 4 see original reference for details [38]) were constructed based on the identified and isolated fragments and constitute part of the claimed subject matter. The described expression of the Dsz+ trait in both a related and non-related heterologous host detailed in the patent, seems to indicate that pTOXI-1 (see patent document [38]) carries all of the genetic information required for conversion of DBT to 2-HBP. 

Freitag A, Rapp H, Heide L et al (2005) Metabolic engineering of aminocoumarins inactivation of the methyltransferase gene cloP and generation of new clorobiocin derivatives in a heterologous host. ChemBioChem 6 1411-1418... 

CM Kao, L Katz, C Khosla. Engineered biosynthesis of a complete macrolactone in a heterologous host. Science 265 509-512, 1994. 

Wild type cells often contain several enzymes which carry out the same reaction. Unfortunately, in many cases these enzymes produce compounds with opposite stereoselectivity. Therefore, whole cells in which such enzymes are present cannot be applied for the synthesis of enantiomerically pure products. To increase the stereoselectivity of a whole cell reaction, recombinant DNA techniques need to be applied. Very common is the overexpression of the enzyme, which catalyzes the particular reaction in a suitable heterologous host such as E. coli. The simultaneous overexpression of an enzyme which catalyzes the regeneration of the consumed cofactor is highly efficient. Ideally, growing cells should provide simultaneously the enzyme for the desired reaction as well as the cofactor regenerating enzyme. Such so-called designer cells seem to be very promising for technical applications. 

Facile expression of enzymes using heterologous hosts. 

Genomic studies disclosed that many of those uncultivable microbes contain the potential to produce new secondary metabolites and there are a variety of routes to access this pool of novel natural products. For example, the community DNA gene clusters can be isolated and the genetic information for secondary metabolism expressed in heterologous hosts.45 47 A more rewarding approach may be to focus on improved cultivation methods.40,48... 

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