Streptomyces secretion vector

摘要

Cloning vectors are disclosed to obtain secretion of a desired protein from a host Streptomyces when a structural gene coding for the protein is inserted into the vector. The vector has: (1) regulatory DNA that includes a promoter sequence effective to start transcription in the host Streptomyces and DNA that encodes a ribosome-binding site; (2) a DNA sequence that codes for a signal sequence that occurs naturally in a Streptomyces strain or that derives from such a DNA sequence; and (3) at least one engineered restriction endonuclease recognition site positioned for the insertion of a structural gene, the DNA that encodes a signal sequence and attached structural gene being transcribed and translated together under the control of the regulatory DNA. Expression vectors are disclosed which include a structural gene coding for a desired protein so positioned. Streptomyces cells containing the vector and methods of using them to produce the desired protein are disclosed. Finally, an alkaline phosphatase gene is inserted in secretion vectors for use in a method of evaluating the ability of those vectors to cause secretion in host gram positive bacteria; the method may be used to evaluate either a potential host or a potential secretion vector.