Lack of functional complementation between Bordetella pertussis filamentous hemagglutinin and Proteus mirabilis HpmA hemolysin secretion machineries.
The gram-negative bacterium Bordetella pertussis has adapted specific secretion machineries for each of its major secretory proteins. In particular, the highly efficient secretion of filamentous hemagglutinin (FHA) is mediated by the accessory protein FhaC. FhaC belongs to a family of outer membrane proteins which are involved in the secretion of large adhesins or in the activation and secretion of Ca2+-independent hemolysins by several gram-negative bacteria. FHA shares with these hemolysins a 115-residue-long amino-proximal region essential for its secretion. To compare the secretory pathways of these hemolysins and FHA, we attempted functional transcomplementation between FhaC and the Proteus mirabilis hemolysin accessory protein HpmB. HpmB could not promote the secretion of FHA derivatives. Likewise, FhaC proved to be unable to mediate secretion and activation of HpmA, the cognate secretory partner of HpmB. In contrast, ShlB, the accessory protein of the closely related Serratia marcescens hemolysin, was able to activate and secrete HpmA. Two invariant asparagine residues lying in the region of homology shared by secretory proteins and shown to be essential for the secretion and activation of the hemolysins were replaced in FHA by site-directed mutagenesis. Replacements of these residues indicated that both are involved in, but only the first one is crucial to, FHA secretion. This slight discrepancy together with the lack of functional complementation demonstrates major differences between the hemolysins and FHA secretion machineries.
Jacob-Dubuisson
F
F
INSERM U447, Institut Pasteur de Lille, France.
Buisine
C
C
Willery
E
E
Renauld-Mongénie
G
G
Locht
C
C
D018829:Adhesins, Bacterial / Q000378:metabolism*; D000595:Amino Acid Sequence; D001216:Asparagine / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D001886:Bordetella pertussis / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D005816:Genetic Complementation Test; D006388:Hemagglutinins / Q000378:metabolism*; D006460:Hemolysin Proteins / Q000378:metabolism*; D008565:Membrane Proteins; D016297:Mutagenesis, Site-Directed; D011513:Proteus mirabilis / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins; D013045:Species Specificity; D010566:Virulence Factors, Bordetella
D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D006388:Hemagglutinins; D006460:Hemolysin Proteins; C064194:HpmA hemolysin; C104106:HpmB protein, Proteus mirabilis; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D010566:Virulence Factors, Bordetella; C098052:fhaC protein, Bordetella pertussis; C065273:filamentous hemagglutinin adhesin, Bordetella pertussis; D001216:Asparagine