CLONING AND EXPRESSION OF THE GENE ENCODING THE GLUTAMIC ACID-SPECIFIC PROTEASE OF STREPTOMYCES-GRISEUS ATCC10137

The gene (sgpE) encoding the Streptomyces griseus glutamic-acid-specif ic protease (SGPE) was cloned and sequenced. The sgpE gene contained a n open reading frame of 1065 nucleotides encoding 355 amino acids (aa) with a pre-propeptide of 168 aa ending at Glu, suggesting the probabi lity of auto-proteolysis. A Streptomyces lividans strain carrying the plasmid-borne sgpE under control of the traA gene promoter secreted ma ture SGPE into the culture medium. Compared to Staphylococcus aureus p rotease V8, the purified SGPE was more resistant to urea. It is sugges ted that SGPE would be a useful tool for site-specific processing of p roteins, even under denaturing conditions.