| 摘要 |
A DNA-fragment which comprises a novel signal DNA sequence coding for a signal peptide and which downstream thereof comprises or can be provided with an insertion site for a gene or a portion thereof coding for a selected protein or polypeptide, such that expression of the signal DNA sequence together with said gene or portion thereof produces a precursor of the selected protein or polypeptide, from which the signal peptide is cleaved off during secretion of the protein or polypeptide product through a cell membrane. The signal DNA sequence is characterized by being derived from a staphylococcal protein A coding gene, or being a chemically synthetized equivalent thereto. A process for its preparation as well as a cloning vehicle comprising such a DNA-fragment and the preparation thereof are provided. Also a microorganism transformed by such a cloning vehicle and a process for the preparation thereof are provided. Finally there are provided a recombinant DNA molecule comprising such a cloning vehicle into which a gene or a portion thereof coding for a selected protein or polypeptide has been inserted, the process for preparing such a recombinant DNA molecule, a microorganism transformed thereby and a process for its preparation. |
