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 .beta.-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.