title: Secretion and processing of staphylococcal nuclease by Bacillus subtilis.
abstract: We have studied the secretion and processing of Staphylococcus aureus nuclease in Bacillus subtilis. We show that the initial species of nuclease found in the cell supernatants during short-term radioactive labeling (pulse-chase) had a molecular weight of approximately 18,800 and comigrated in a sodium dodecyl sulfate-polyacrylamide gel with staphylococcal nuclease B. This nuclease B form was processed to the mature nuclease A extracellularly by a phenylmethylsulfonyl fluoride-sensitive protease. The nuclease B-processing site is a consensus signal peptidase site, and the processing of nuclease B was coupled to secretion as judged by pulse-chase experiments. The nuclease A was shown by microsequencing of the N terminus to be 2 amino acid residues shorter than the nuclease A described for S. aureus Foggi. The nuclease B form was still the first species found in the culture supernatant after removal of the N-terminal 26 amino acids of the native 60-amino-acid signal peptide. However, removal of the N-terminal 72 amino acids abolishes secretion of any nuclease form and leads to the intracellular accumulation of nuclease.
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D004274:DNA, Recombinant; D010450:Endopeptidases / Q000378:metabolism; D005822:Genetic Vectors; D008565:Membrane Proteins; D008836:Micrococcal Nuclease / Q000235:genetics / Q000378:metabolism*; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D011499:Protein Processing, Post-Translational; D021382:Protein Sorting Signals / Q000378:metabolism*; D012697:Serine Endopeptidases; D013211:Staphylococcus aureus / Q000201:enzymology* / Q000235:genetics
chemical_list: D004274:DNA, Recombinant; D008565:Membrane Proteins; D021382:Protein Sorting Signals; D010664:Phenylmethylsulfonyl Fluoride; D008836:Micrococcal Nuclease; D010450:Endopeptidases; D012697:Serine Endopeptidases; C026515:type I signal peptidase