| 摘要 |
PURPOSE:A plasmid vector, prepared by inactivating the immunological function for colicin E1 on ColE1 plasmid, and varying a gene in the colicin E1 protein to produce the colicin E1 vigorously at a specified temperature, and capable of remarkably increasing the amount of the plasmid multiplied in the host microorganism. CONSTITUTION:An exogenous gene capable of taking part in the tolerance to ampicillin transposon and kanamycin is inserted in a gene capable of taking part in the production of a protein capable of exhibiting the immunity against the colicin E1 on ColE1 plasmid to inactivate the immunological function. The resultant plasmid or a host microorganism containing the plasmid is then irradiated with ultraviolet light or brought into contact with a variation inducing agent, e.g. N-methyl-N'-nitro-N-nitrosoguanidine, to give a plasmid vector varied to produce colicin E1 vigorously at 37 deg.C even when the colicin E1 production is not induced. |
