Temperature-inducible secretion expression vectors and their use in prokaryotic cells.

摘要

Temperature-inducible secretion expression vectors have been constructed and used to express heterologous proteins in E. coli. The vectors use a promoter comprising a nucleotide capable of binding the CI repressor to provide for temperature-inducible expression from the promoter. Secretion of the native heterologous protein is achieved by replacing the coding region adjacent to the promoter signal sequence with a DNA sequence encoding the heterologous protein. The secretion expression vector is transformed into a host cell which is then grown and induced to express the heterologous protein. No expression is seen at 30 DEG C, but upon induction at 42 DEG C, protein is produced. Expression levels of 5-10% of total protein are seen. The heterologous protein is shown to be correctly processed and biologically active. These vectors can be used to express and secrete a protein of interest in prokaryotic cells lacking a temperature-sensitive mutation by inserting the appropriate gene in phase with the signal sequence.