Subtilisin-like autotransporter serves as maturation protease in a bacterial secretion pathway.
Proteins of Gram-negative bacteria destined to the extracellular milieu must cross the two cellular membranes and then fold at the appropriate time and place. The synthesis of a precursor may be a strategy to maintain secretion competence while preventing aggregation or premature folding (especially for large proteins). The secretion of 230 kDa filamentous haemagglutinin (FHA) of Bordetella pertussis requires the synthesis and the maturation of a 367 kDa precursor that undergoes the proteolytic removal of its approximately 130 kDa C-terminal intramolecular chaperone domain. We have identified a specific protease, SphB1, responsible for the timely maturation of the precursor FhaB, which allows for extracellular release of FHA. SphB1 is a large exported protein with a subtilisin-like domain and a C-terminal domain typical of bacterial autotransporters. SphB1 is the first described subtilisin-like protein that serves as a specialized maturation protease in a secretion pathway of Gram-negative bacteria. This is reminiscent of pro-protein convertases of eukaryotic cells.
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INSERM U447, IBL, Institut Pasteur de Lille, 1 rue Calmette, 59019 Lille Cedex, France.
Antoine
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Drobecq
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Locht
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Jacob-Dubuisson
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D018829:Adhesins, Bacterial / Q000378:metabolism*; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D001426:Bacterial Proteins; D001483:Base Sequence; D001886:Bordetella pertussis / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D006388:Hemagglutinins / Q000378:metabolism*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011498:Protein Precursors / Q000378:metabolism; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D012697:Serine Endopeptidases / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D020860:Subtilisin / Q000502:physiology*; D010566:Virulence Factors, Bordetella
D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D006388:Hemagglutinins; D011498:Protein Precursors; D010566:Virulence Factors, Bordetella; C065273:filamentous hemagglutinin adhesin, Bordetella pertussis; D012697:Serine Endopeptidases; C437318:SphB1 protein, Bordetella pertussis; D020860:Subtilisin