title: The flaFIX gene product of Salmonella typhimurium is a flagellar basal body component with a signal peptide for export.
abstract: flaFIX, the structural gene for the periplasmic P ring of the flagellar basal body of Salmonella typhimurium, was cloned. Two gene products with apparent molecular weights of 38,000 and 40,000 were identified by minicell analysis. Data from pulse-chase and membrane fractionation experiments and data on the inhibitory effect of the proton ionophore carbonyl cyanide m-chlorophenylhydrazone all indicated that the 40-kilodalton protein was a precursor form which, after export across the cytoplasmic membrane accompanied by cleavage of a signal peptide, gave rise to the mature protein in the periplasm. The N-terminal amino acid sequence of the FlaFIX protein, predicted from the DNA sequence, conformed well to known signal peptide sequences. The results indicate that the P-ring protein of the basal body (unlike flagellin and possible some other external flagellar components) crosses the cytoplasmic membrane in a conventional signal peptide-dependent manner.
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D005407:Flagella / Q000378:metabolism*; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D008954:Models, Biological; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D021382:Protein Sorting Signals / Q000235:genetics / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D011498:Protein Precursors; D021382:Protein Sorting Signals