EXPRESSION OF THE CARBOXYPEPTIDASE-T GENE FROM THERMOACTINOMYCES-VULGARIS IN STABLE PROTOPLAST TYPE L-FORMS OF PROTEUS-MIRABILIS

The structural gene of the carboxypeptidase T (cpt) was successfully e xpressed in cell wall-less L-form cells of Proteus mirabilis. The DNA sequence encoding the PhoA leader peptide was fused with a truncated c pt gene encoding the mature enzyme. The modified gene in a pUC-based k anamycin resistance vector under the control of the Inc promoter was t ransformed into L-form cells of P. mirabilis. They were able to produc e the recombinant CpT both as a secretory and as a cell-bound insolubl e form. The co-secretory processing of the PhoA leader peptide was qui te efficient. The yield of the secreted CpT was not less than 20 mg l( -1) and should be improvable. (C) 1998 Federation of European Microbio logical Societies. Published by Elsevier Science B.V.