Evolution of the Chaperone/Usher Assembly Pathway: Fimbrial Classification Goes Greek

Nuccio, Sean Paul; Bäumler, Andreas J.

doi:10.1128/mmbr.00014-07

Cited by 293 publications

(481 citation statements)

References 379 publications

Supporting

Mentioning

456

Contrasting

Unclassified

Order By: Relevance

“…However, there is always only one outer membrane (OM) usher present. As a consequence, Nuccio & Bäumler [8] proposed a classification scheme based on the usher protein. The fimbrial usher protein (FUP) family is distributed among the Proteobacteria, Cyanobacteria and Deinococcus-Thermus phyla [9].…”

Section: Classification Of Chaperone -Usher Pathwaymentioning

confidence: 99%

“…The CU secretion systems are mostly grouped into gene clusters, some of them identified as operons, with a minimum of an usher-, a chaperone-and a fimbrial/pilus subunit-encoding gene [8]. The chaperone and usher proteins are the accessory proteins needed to assemble pilus subunits into a pilus and secrete the assembled pilus.…”

Section: Classification Of Chaperone -Usher Pathwaymentioning

confidence: 99%

See 1 more Smart Citation

Chaperone–usher pathways: diversity and pilus assembly mechanism

Büsch

Waksman

2012

Phil. Trans. R. Soc. B

121

107

View full text Add to dashboard Cite

Up to eight different types of secretion systems, and several more subtypes, have been described in Gram-negative bacteria. Here, we focus on the diversity and assembly mechanism of one of the beststudied secretion systems, the widespread chaperone-usher pathway known to assemble and secrete adhesive surface structures, called pili or fimbriae, which play essential roles in targeting bacterial pathogens to the host.

show abstract

Section: Classification Of Chaperone -Usher Pathwaymentioning

confidence: 99%

Section: Classification Of Chaperone -Usher Pathwaymentioning

confidence: 99%

Chaperone–usher pathways: diversity and pilus assembly mechanism

Büsch

Waksman

2012

Phil. Trans. R. Soc. B

121

107

View full text Add to dashboard Cite

show abstract

“…However, subunits in complex with PapD are not completely condensed but instead are in an open conformation that is "primed" for assembly (20). DSC has been demonstrated both for P and type 1 pilus systems, as well as for Sfa, Saf, Caf, Fml, and others (22), demonstrating the prototypical nature of P pili.…”

mentioning

confidence: 99%

Domain activities of PapC usher reveal the mechanism of action of an Escherichia coli molecular machine

Volkan¹,

Ford

Pinkner³

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

P pili are prototypical chaperone-usher pathway-assembled pili used by Gram-negative bacteria to adhere to host tissues. The PapC usher contains five functional domains: a transmembrane β-barrel, a β-sandwich Plug, an N-terminal (periplasmic) domain (NTD), and two C-terminal (periplasmic) domains, CTD1 and CTD2. Here, we delineated usher domain interactions between themselves and with chaperone-subunit complexes and showed that overexpression of individual usher domains inhibits pilus assembly. Prior work revealed that the Plug domain occludes the pore of the transmembrane domain of a solitary usher, but the chaperone-adhesinbound usher has its Plug displaced from the pore, adjacent to the NTD. We demonstrate an interaction between the NTD and Plug domains that suggests a biophysical basis for usher gating. Furthermore, we found that the NTD exhibits high-affinity binding to the chaperone-adhesin (PapDG) complex and low-affinity binding to the major tip subunit PapE (PapDE). We also demonstrate that CTD2 binds with lower affinity to all tested chaperone-subunit complexes except for the chaperone-terminator subunit (PapDH) and has a catalytic role in dissociating the NTD-PapDG complex, suggesting an interplay between recruitment to the NTD and transfer to CTD2 during pilus initiation. The Plug domain and the NTDPlug complex bound all of the chaperone-subunit complexes tested including PapDH, suggesting that the Plug actively recruits chaperone-subunit complexes to the usher and is the sole recruiter of PapDH. Overall, our studies reveal the cooperative, active roles played by periplasmic domains of the usher to initiate, grow, and terminate a prototypical chaperone-usher pathway pilus.biolayer interferometry | macromolecular assembly | urinary tract infections | virulence factor | bacterial pathogenesis

show abstract

“…The Fim operon contains 6 genes, which are predicted to encode the major pilin subunit protein (fimA), a gene of unknown function (fimB), an outer membrane usher (fimC), a periplasmic chaperone (fimD), and 2 minor pilus subunits (fimEF). Based on the aa sequence of the outer membrane usher protein (FimC) and gene order, the Aeromonas salmonicida pilus is in the same group (π) as the pyelonephritis-associated (P) pili that allow uropathogenic Escherichia coli to adhere to kidney epithelial cells (Nuccio & Bäumler 2007). P fimbriae are composed of a rigid helical shaft that ends in a thinner flexible tip fibrillum, and the single adhesive subunit is carried at the distal end of this fibrillum.…”

Section: Discussionmentioning

confidence: 99%

Aeromonas salmonicida Type I pilus system contributes to host colonization but not invasion

Dacanay¹,

Boyd²,

Fast³

et al. 2010

Dis. Aquat. Org.

View full text Add to dashboard Cite

The host-adherence strategies employed by Aeromonas salmonicida subsp. salmonicida, the etiological agent of an infectious bacteremia of salmonids, are poorly understood. In addition to the outer protein coat or S-layer, A. salmonicida has both Type I and Type IV pili loci. The A. salmonicida Type I or Fim pilus is encoded by an operon with genes for a chaperone, an usher, and 3 pilus subunits and is predicted to be similar to the Pap fimbriae of uropathogenic Escherichia coli, which are considered significant virulence factors. A Fim-deficient strain of A. salmonicida strain A449, Δfim, was created by deleting this operon. Virulence of Δfim was unchanged in direct live challenges of Atlantic salmon Salmo salar L., a natural host for A. salmonicida. A measure of clinically inapparent (covert) infections suggested Fim was required to establish or maintain a covert infection. This was confirmed by an ex vivo adherence and invasion assay using freshly excised salmon gastrointestinal (GI) tract, which showed that, compared to the parental strain, the ability of the isogenic Δfim mutant strain to adhere to the salmon GI tract was reduced but, once adhered, its ability to invade was unchanged. Thus the Fim pilus functions as an adhesin in A. salmonicida and the presence of a functional Fim improved the efficiency of A. salmonicida infection of Atlantic salmon. KEY WORDS: Pilin · Adhesin · Furunculosis · VirulenceResale or republication not permitted without written consent of the publisher Dis Aquat Org 88: 199-206, 2010 epithelium by a trans-cellular route and that this translocation requires bacteria with intact and functional surface structures. Our continued interest in A. salmonicida adhesins leads us to ask if we could identify factors important for adherence to salmon intestinal tissue.The most well studied Aeromonas salmonicida adhesin is its outer protein coat, the S-layer, the major protein constituent of which is VapA. While the S-layer has long been demonstrated to be both an important virulence factor and an adhesin (Ishiguro et al. 1981, Trust et al. 1983, Garduño et al. 1992, Kay & Trust 1997, Garduño et al. 2000, VapA-deficient strains may still be infectious (Ellis et al. 1988, Olivier 1990. In addition to the S-layer, A. salmonicida strain A449 also has genes for at least 4 specific adhesion systems: Tap, Flp, MSHA, and Fim (Reith et al. 2008). The first 3 are Type IV pili and have been characterized elsewhere (Masada et al. 2002). The latter system, Fim, is predicted to encode a Type I pilus, similar to the fimbriae of pathogenic Escherichia coli that are considered to be important virulence factors in that organism. The present study reports on the contribution of Fim to A. salmonicida strain A449 virulence as assessed by a Fim-deficient isogenic laboratory strain. MATERIALS AND METHODSBacterial strains and growth conditions. Bacteria and plasmids used in the present study are listed in Table 1. The parental strain for all knockouts was Aeromonas salmonicida subsp. salmonicida strain ...

show abstract

Evolution of the Chaperone/Usher Assembly Pathway: Fimbrial Classification Goes Greek

Cited by 293 publications

References 379 publications

Chaperone–usher pathways: diversity and pilus assembly mechanism

Chaperone–usher pathways: diversity and pilus assembly mechanism

Domain activities of PapC usher reveal the mechanism of action of an Escherichia coli molecular machine

Aeromonas salmonicida Type I pilus system contributes to host colonization but not invasion

Contact Info

Product

Resources

About