| 摘要 |
PURPOSE:A novel plasmid having a large number of copies, improved stability retention, not falling off in cell multiplication, containing three kinds of DNA fragments having specific genes. CONSTITUTION:A plasmed (e.g., plasmid pMTY-4 shown by the figure) capable of growing autonomously in a cell of Escherichia coil, containing a DNA fragment having a gene to rule biosynthesis of tryptophan synthase having promoter function to develop trp(A)B derived from Escherichia coli and both the genes, a DNA fragment having a gene to rule replicating function in lambda NOP range obtained by cleaving lambda phage DNA with restriction enzyme BamHI and a DNA fragment to rule autonomous replication of Col EI plasmid derived from plasmid pBR322. |
