Phage T4 expression vector: protection from proteolysis

We have developed an efficient method for the expression of heterologous genes during infection by T4, a bacteriophage known to inhibit the proteolytic systems of Escherichia coli. This system enables us to clone genes in a plasmid expression vector and move them readily into T4. We have used lacZ as a reporter gene to show that both plasmid and phage exhibit low basal expression or high-level expression under the control of a T7 promoter. This system promises a possible solution to the problem of degradation and/or toxicity of overproduced proteins.