title: Membrane localization and topology of the Yersinia pestis YscJ lipoprotein.
abstract: The localization and membrane topology of the Yersinia pestis YscJ lipoprotein, an essential component of the type III secretion apparatus, was investigated. YscJ was demonstrated to be an inner membrane (IM) lipoprotein that is anchored to the periplasmic face of the IM via an N-terminal lipid moiety and via a C-terminal transmembrane (TM) domain. Localization of the N-terminal lipid moiety to the IM occurred regardless of the amino-acid residues found in the +2 or +3 positions. IM localization was dependent upon an intact N-terminal domain (amino acids +1 to +61), suggesting that this region plays a role in YscJ localization. In contrast, the YscJ C-terminal domain and TM domain were not required for IM localization. N-terminal sequence analysis demonstrated that a significant proportion of membrane-localized YscJ lacks N-acylation, the final modification required for Lol-dependent transport of a lipoprotein to the OM. Interestingly, attachment of the N-terminus to the IM was required for YscJ function; however, the YscJ secretion signal and lipo-box could be functionally replaced by the first TM domain of the YscV protein, suggesting that the mechanism of attachment to the IM was not critical.
authors.affiliation: Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33101, USA.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Silva-Herzog
authors.affiliation: Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33101, USA.
authors.forename: Franco
authors.initials: F
authors.lastname: Ferracci
authors.affiliation: Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33101, USA.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Jackson
authors.affiliation: Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33101, USA.
authors.forename: Sabrina S
authors.initials: SS
authors.lastname: Joseph
authors.affiliation: Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33101, USA.
authors.forename: Gregory V
authors.initials: GV
authors.lastname: Plano
mesh_terms: D000215:Acylation; D000217:Acyltransferases / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008055:Lipids / Q000032:analysis; D008074:Lipoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D019897:Periplasm / Q000378:metabolism; D033903:Periplasmic Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D021382:Protein Sorting Signals; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics; D017384:Sequence Deletion; D015010:Yersinia pestis / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D008055:Lipids; D008074:Lipoproteins; D033903:Periplasmic Proteins; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D000217:Acyltransferases