DNA FRAGMENT CONTAINING GENE PARTICIPATING IN STABILIZATION OF PLASMID IN HOST

摘要

PURPOSE:To provide a DNA fragment containing a gene participating in the function for stably keeping a plasmid in its host which is a glutamic acid- producing coryne-type bacterial strain. CONSTITUTION:DNA of a plasmid pAG1 of Corynebacterium melassecola 22243 (FERM BP-560) is prepared and digested with a restriction enzyme ECoRI. Separately, a vector plasmid having relatively low stability in a host cell is digested with ECoRI. The digested DNA is linked with the digested plasmid by ligase-treatment and the product is introduced by transformation into a plasmid cured strain obtained by removing plasmid pAG1 from Corynebacterium melassecola 22243. A DNA fragment of about 4.3kb and containing stabilizing factor is separated from the transformant. The fragment is integrated into plasmid pAG14 or a plasmid originated from pAG50 to obtain pAG141 or pAG51, which is used as a vector in the case of using a glutamic acid-producing coryne- type bacterial strain as a host.