Hetero- and Autoprocessing of the Extracellular Metalloprotease (Mpr) in Bacillus subtilis

Abstract

Most proteases are synthesized as inactive precursors which are processed by proteolytic cleavage into a mature active form, allowing regulation of their proteolytic activity. The activation of the glutamic-acid-specific extracellular metalloprotease (Mpr) of Bacillus subtilis has been examined. Analysis of Mpr processing in defined protease-deficient mutants by activity assay and Western blotting revealed that the extracellular protease Bpr is required for Mpr processing. pro-Mpr remained a precursor form in bpr-deficient strains, and glutamic-acid-specific proteolytic activity conferred by Mpr was not activated in bpr-deficient strains. Further, purified pro-Mpr was processed to an active form by purified Bpr protease in vitro. We conclude that Mpr is activated by Bpr in vivo, and that heteroprocessing, rather than autoprocessing, is the major mechanism of Mpr processing in vivo. Exchange of glutamic acid for serine in the cleavage site of Mpr (S93E) allowed processing of Mpr into its mature form, regardless of the presence of other extracellular proteases, including Bpr. Thus, a single amino acid change is sufficient to convert the Mpr processing mechanism from heteroprocessing to autoprocessing.

Biodegradation of feather waste by extracellular keratinases and gelatinases from Bacillus spp.

“…Currently, a large proportion of the commercially available alkaline peptidases are produced by Bacillus species because of their high pH and temperature stability (Tari et al 2006). Bacteria of the genus Bacillus, usually secrete two types of extracellular peptidases, a neutral and an alkaline peptidase (Park et al 2004;Tang et al 2004). Significant keratinolytic and proteolytic activity was observed for all three species studied in this work and this activity responded to changes in pH and temperature.…”

Purification and Characterization of Two Novel Halotolerant Extracellular Proteases fromBacillus subtilisStrain FP-133

“…Some reports state that B. subtilis secretes several types of extracellular protease, including the alkaline serine protease subtilisin, neutral protease A, bacillopeptidase F, metalloprotease, neutral protease B, and cell wall-associated extracellular protease. 9,22,23) However, only one halotolerant protease from Bacillus subtilis has been reported.…”

CodY Regulates Expression of the Bacillus subtilis Extracellular Proteases Vpr and Mpr

“…In this work, we demonstrated that the genes coding for two B. subtilis minor extracellular proteases, Vpr and Mpr (36,39,40,65,66), are also repressed by CodY. CodY repression at the vpr locus is exerted by binding at the single CodY-binding site located in the vicinity of the transcription start point of the gene, implying that the mechanism of repression is by competition with RNA polymerase.…”