In vivo processing of Staphylococcus aureus lipase.
The Staphylococcus aureus lipase gene encodes a 76-kDa protein. Extracellular lipase purified from culture supernatants is only 45 to 46 kDa, however. We show that the lipase is secreted in vivo as an 82-kDa protein with full enzymatic activity. It is then sequentially processed, both in culture and in cell-free supernatants, to a mature, 45- to 46-kDa protein. Protein sequencing demonstrates that the N-terminal region of the 82-kDa prolipase, comprising 295 amino acids, is cleaved from the central and C-terminal moieties, which contain the active site. A metallocysteine protease is probably responsible for initiating this processing. The extremely hydrophobic, mature lipase is resistant to further protease degradation and retains the full catalytic activity of the prolipase.
Rollof
J
J
Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110-1093.
Normark
S
S
D000595:Amino Acid Sequence; D015153:Blotting, Western; D008049:Lipase / Q000276:immunology / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011498:Protein Precursors / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D013211:Staphylococcus aureus / Q000201:enzymology*
D011498:Protein Precursors; D008049:Lipase