HIGH COPY-NUMBER PLASMID VECTORS, PRODUCTION AND USE THEREOF

摘要

AbstractThe invention relates to new plasmidvectors which have a substantially higher copynumber pro cell than the hitherto known plasmids,e.g. pBR322. The increase of copy number and, ac-cordingly, of the gene product is the result of amutation in the gene section responsible for theproduction of the repressor of plasmid replication.In case of pBR322 or a derivative thereof which hasthe same replication region the desired increase ofthe copy number can be achieved by a G ? T pointmutation in position 3074, following the numberingof the original pBR322.The invention includes both the high copy--number plasmid vectors and the methods for theirpreparation. Microorganisms containing and repli-cating any of the high copy-number plasmids (pHC-plasmids) are also within the scope of the inven-tion.