title: Inter-molecular degradation of signal peptidase I in vitro.
abstract: Highly purified preparations of signal peptidase I (36 kDa) were found to undergo an apparent inter-autocatalytic degradation at 4 degrees C and 37 degrees C. The disappearance of the 36 kDa protein coincided with the stable appearance of a 31 kDa and a 5 kDa species. Amino-terminal sequencing of the 31 kDa product indicated a site specific cleavage following Ala38-Gln-Ala of signal peptidase I. The 31 kDa fragment was purified and shown to have 100-fold less activity than the native enzyme, with pre-maltose binding protein as a substrate.
authors.affiliation: Wellcome Research Laboratories, Department of Molecular Genetics and Microbiology, Research Triangle Park, NC 27709.
authors.forename: T L
authors.initials: TL
authors.lastname: Talarico
authors.forename: I K
authors.initials: IK
authors.lastname: Dev
authors.forename: P J
authors.initials: PJ
authors.lastname: Bassford
authors.forename: P H
authors.initials: PH
authors.lastname: Ray
mesh_terms: D018528:ATP-Binding Cassette Transporters; D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000378:metabolism; D010450:Endopeptidases / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins; D007700:Kinetics; D058619:Maltose-Binding Proteins; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009004:Monosaccharide Transport Proteins; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology; D011498:Protein Precursors / Q000378:metabolism; D012697:Serine Endopeptidases
chemical_list: D018528:ATP-Binding Cassette Transporters; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D058619:Maltose-Binding Proteins; D008565:Membrane Proteins; D009004:Monosaccharide Transport Proteins; D010446:Peptide Fragments; D011480:Protease Inhibitors; D011498:Protein Precursors; C461599:maltose transport system, E coli; D010450:Endopeptidases; D012697:Serine Endopeptidases; C026515:type I signal peptidase