Hetero- and autoprocessing of the extracellular metalloprotease (Mpr) in Bacillus subtilis.
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.
Park
Chi Hye
CH
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Korea. smbyun@kaist.ac.kr
Lee
Sang Jun
SJ
Lee
Sung Gu
SG
Lee
Weon Sup
WS
Byun
Si Myung
SM
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D004789:Enzyme Activation; D008969:Molecular Sequence Data; D012697:Serine Endopeptidases / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology
D001426:Bacterial Proteins; C108269:BSase protein, Bacillus subtilis; C445309:Epr serine proteinase; D012697:Serine Endopeptidases; C038477:bacillopeptidase F