Characterization of the gene encoding the glutamic-acid-specific protease of Streptomyces griseus

The complete gene sequence (sprE) for the glutamic-acid-specific serine protease (SGPE) of the gram-positive bacterium Streptomyces griseus is reported. The sprE gene encodes a 355 amino acid pre-pro-mature enzyme. The presence of a glutamic acid residue at the junction of the pro and mature segments of the protein suggests that the enzyme is self-processing. SGPE was found to have extensive homology with the S. griseus proteases A and B. However, there is an additional segment to the pro region of SGPE, lacking in proteases A and B, which has significant homology to the pro region of the alpha-lytic protease of the gram-negative bacterium Lysobacter enzymogenes. Expression of recombinant SGPE in Bacillus subtilis is also reported, and the enzyme is shown to be self-processing.