NOVEL SHUTTLE VECTOR

摘要

A bifidobacteria microorganism (BM)/E. coli shuttle vector, which has a wide host range in BM, yields a large copy number and allows the overexpression of a desired protein when it is used as an expression vector; an expression vector that allows the expression of a desired gene in BM using the shuttle vector; BM transformed with the expression vector; and an antitumor agent containing the BM as an active ingredient are provided. The BM/E. coli shuttle vector which contains the replication origin (oriV)-repB region of pTB6, a region derived from pTB6 not containing MembB, MobA, OrfI and oriT regions, the replication origin (oriC) region of E. coli, and a plasmid region derived from E. coli in which DNA encoding the N-terminal region of ß-lactamase which is an expression product of an ampicillin resistance gene (ampR) has been deleted, and whose average copy number is 6 to 30 is constructed.