L-rhamnose-inducible expression systems
AssigneeBASF SE
InventorsMaria Keβeler, Thomas Zelinski, Bernhard Hauer
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Abstract
The present invention relates to methods for expressing nucleic acid sequences in prokaryotic host cells, where at least one DNA construct which is capable of episomal replication in a host cell and which comprises a nucleic acid sequence to be expressed under the transcriptional control of an L-rhamnose-inducible promoter, where the promoter is heterologous with regard to the nucleic acid sequence, is introduced into the host cell and the expression of he nucleic acid sequence is induced by addition of L-rhamnose, wherein the prokaryotic host cell is at least deficient with regard to an L-rhamnose isomerase.
Claims15
A method for expressing nucleic acid sequences in prokaryotic host cells by high-density cell fermentation, comprising;
- a) introducing into a prokaryotic host cell at least one DNA construct which is capable of episomal replication in said prokaryotic host cell and comprises a nucleic acid sequence to be expressed under the transcriptional control of an L-rhamnose-inducible promoter, wherein said L-rhamnose-inducible promoter is heterologous with regard to said nucleic acid sequence,
- b) selecting prokaryotic host cells which comprise said DNA construct in episomal form, and
- c) inducing the expression of said nucleic acid sequence by addition of L-rhamnose to a high-density cell culture of said selected prokaryotic host cells, wherein the concentration of L-rhamnose in the medium is from 0.01 g/l to 0.5 g/l,
- wherein the prokaryotic host cell is at least deficient with regard to L-rhamnose isomerase.
An isolated prokaryotic host cell capable of producing recombinant proteins by high-density cell fermentation, wherein said host cell is at least deficient with regard to L-rhamnose isomerase and comprises at least one DNA construct, wherein the at least one DNA construct is capable of replication in said host cell and comprises a nucleic acid sequence to be expressed under the transcriptional control of an L-rhamnose-inducible promoter in the presence of L-rhamnose at a concentration from 0.01 g/l to 0.5 g/l in high-density cell fermentation, wherein said L-rhamnose-inducible promoter is heterologous with regard to said nucleic acid sequence.
Dependencies are inferred from the claim text.