Plasmid replication origin increasing the copy number of the plasmid containing the said origin

摘要

A DNA sequence derived by the mutation from a ColE1-type replication origin is provided, wherein the sequence is characterized in that it includes at least one of the following mutations, which are defined in relation to the wild ColE1 origin: a Guanine to Adenine transversion in position 2976; and a Guanine deletion in position 3057. This sequence increases the number of copies of the plasmids which include it. Plasmids containing the replication origin, and their uses in the amplification of DNA sequences and the production of polypeptides by genetic engineering, are also disclosed.