abstract |
The present invention relates to a method for improving the extracellular secretion level of Escherichia coli recombinant proteins. The method of homologous recombination integrates a gene fragment comprising 1-4 SD sequences into coding D-alanyl-D-alanine carboxypeptidase Between the promoter of DacA and the gene encoding DacA. The present invention improves the expression of D,D-carboxypeptidase DacA by integrating different SD sequences between the promoter of Escherichia coli DacA gene and the DacA encoding gene, thereby improving the extracellular secretion level of Escherichia coli recombinant protein. |