title: The major outer membrane lipoprotein and new lipoproteins share a common signal peptidase that exists in the cytoplasmic membrane of Escherichia coli.
abstract: The cell envelope of Escherichia coli possesses several lipoproteins including the major outer membrane lipoprotein. These lipoproteins are synthesized as a signal peptide-carrying precursor that is subsequently modified with glyceride. In this work, lipoprotein signal peptidase that processes the precursor of the major lipoprotein was partially purified from cells harboring a plasmid that carries the gene for this enzyme (1spA). The enzyme was also active against the glyceride-containing precursors of the peptidoglycan-associated lipoprotein and many additional membrane lipoproteins. The unmodified precursor of the major lipoprotein was not attacked by the enzyme. The enzyme was exclusively localized in the cytoplasmic membrane.
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000201:enzymology; D010450:Endopeptidases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000648:ultrastructure; D008074:Lipoproteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D012697:Serine Endopeptidases; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D008074:Lipoproteins; D008565:Membrane Proteins; D010450:Endopeptidases; D012697:Serine Endopeptidases; C026515:type I signal peptidase