A vector that uses phage signals for efficient synthesis of proteins in Escherichia coli.

I have developed a plasmid vector pCQV2 for high-level expression of proteins in E. coli. The plasmid contains a very strong promoter and translation start point from bacteriophage lambda, and a restriction endonuclease site in which a gene may be placed under control of these initiation signals. The plasmid also contains the gene for a temperature-sensitive repressor of the lambda promoter, allowing 100-fold induction of protein expression. The vector pCQV2 has been used to synthesize SV40 small t antigen at the level of 5-10% of total E. coli protein, representing an order-of-magnitude improvement over previous methods.