NOVEL PLASMID

摘要

PURPOSE:To improve the expression efficiency of tryptophan synthase and to improve the productivity of tryptophan by fermentative or enzymatic process, by changing the orientation of a constituent gene component of a plasmid pMTY-3. CONSTITUTION:Plasmid pMTV-3 is extracted from the cultured cell of Escherichia coli K12 YK2009 (FERM P-7957). A gene fragment controlling the biosynthesis of tryptophan synthase is incised from the plasmid with a restriction enzyme Eco RI and again linked with T4 DNA ligase originated from T4 phage to obtain a plasmid pMTY-8. The yield of the plasmid pMTY-8 is about 10% of the plasmid pMTY-3.