The major structural components of two cell surface filaments of Porphyromonas gingivalis are matured through lipoprotein precursors.
Bacterial cell surface filaments play significant roles in adherence to and invasion of host cells. They are generated by the chaperone/usher pathway system (class I fimbriae), the type II secretion system (type IV pili) and the nucleation-dependent polymerization system (Curli filaments) that are categorized by their modes of expression and assembly. In this study, we found that the periodontal pathogen Porphyromonas gingivalis expressed the major structural components of two cell surface filaments (fimbrilin and the 75 kDa protein) that had extremely long prosequences in their primary gene products. N-terminal amino acid sequencing of the prosequences, treatment of P. gingivalis cells with globomycin, an inhibitor for lipoprotein-specific signal peptidase, amino acid substitution of the cysteine residue of the prosequence of fimbrilin and [(3)H]-palmitic acid labelling implied that fimbrilin and the 75 kDa protein were matured through their lipoprotein precursor forms. Accumulation of precursor forms of fimbrilin and the 75 kDa protein on the cell surface of the gingipain-null mutant revealed that Arg-gingipain processed these precursors on the surface to yield their mature forms, which subsequently assembled into the filamentous structures, suggesting that the transport and assembly of the major component proteins appear to be novel.
Shoji
Mikio
M
Division of Microbiology and Oral Infection, Department of Developmental and Reconstructive Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan.
Naito
Mariko
M
Yukitake
Hideharu
H
Sato
Keiko
K
Sakai
Eiko
E
Ohara
Naoya
N
Nakayama
Koji
K
D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001692:Biological Transport; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism; D036781:Fimbriae Proteins / Q000235:genetics / Q000378:metabolism*; D010861:Fimbriae, Bacterial / Q000378:metabolism; D000080867:Gingipain Cysteine Endopeptidases; D006388:Hemagglutinins / Q000235:genetics / Q000378:metabolism; D008074:Lipoproteins / Q000378:metabolism*; D008954:Models, Biological; D008969:Molecular Sequence Data; D010455:Peptides; D016966:Porphyromonas gingivalis / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism
D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D000080867:Gingipain Cysteine Endopeptidases; D006388:Hemagglutinins; D008074:Lipoproteins; D010455:Peptides; D011480:Protease Inhibitors; D011498:Protein Precursors; C063055:fimbrillin; D036781:Fimbriae Proteins; C017339:globomycin; D003546:Cysteine Endopeptidases