Genome Analysis Reveals Pili in Group B
            <i>Streptococcus</i>

Lauer, Peter; Rinaudo, C. Daniela; Soriani, Marco; Margarit, Immaculada; Maione, Domenico; Rosini, Roberto; Taddei, Anna Rita; Mora, Marirosa; Rappuoli, Rino; Grandi, Guido; Telford, John L.

doi:10.1126/science.1111563

Cited by 296 publications

(254 citation statements)

References 8 publications

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“…Similar pilus assemblies are found for such important human pathogens as Group A and B strep- Table S4. tococci, Streptococcus pneumoniae, and B. cereus (19)(20)(21), but the pilin subunits involved show large variations in size and sequence that mask any possible structural homology.…”

Section: Discussionmentioning

confidence: 99%

The Corynebacterium diphtheriae shaft pilin SpaA is built of tandem Ig-like modules with stabilizing isopeptide and disulfide bonds

Kang

Paterson

Gaspar

et al. 2009

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

104

166

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Cell-surface pili are important virulence factors that enable bacterial pathogens to adhere to specific host tissues and modulate host immune response. Relatively little is known about the structure of Gram-positive bacterial pili, which are built by the sortase-catalyzed covalent crosslinking of individual pilin proteins. Here we report the 1.6-Å resolution crystal structure of the shaft pilin component SpaA from Corynebacterium diphtheriae , revealing both common and unique features. The SpaA pilin comprises 3 tandem Ig-like domains, with characteristic folds related to those typically found in non-pilus adhesins. Whereas both the middle and the C-terminal domains contain an intramolecular Lys–Asn isopeptide bond, previously detected in the shaft pilins of Streptococcus pyogenes and Bacillus cereus , the middle Ig-like domain also harbors a calcium ion, and the C-terminal domain contains a disulfide bond. By mass spectrometry, we show that the SpaA monomers are cross-linked in the assembled pili by a Lys–Thr isopeptide bond, as predicted by previous genetic studies. Together, our results reveal that despite profound dissimilarities in primary sequences, the shaft pilins of Gram-positive pathogens have strikingly similar tertiary structures, suggesting a modular backbone construction, including stabilizing intermolecular and intramolecular isopeptide bonds.

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Section: Discussionmentioning

confidence: 99%

The Corynebacterium diphtheriae shaft pilin SpaA is built of tandem Ig-like modules with stabilizing isopeptide and disulfide bonds

Kang

Paterson

Gaspar

et al. 2009

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

104

166

View full text Add to dashboard Cite

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“…Although important data have been published on their biogenesis and their function (Abbot et al, 2007;Dramsi et al, 2006;Gianfaldoni et al, 2007;Lauer et al, 2005;Maisey et al, 2007;Manetti et al, 2007;Mora et al, 2005;Rosini et al, 2006;Scott & Zähner, 2006;Telford et al, 2006), little is known about the regulation of their synthesis. Besides RogB (Dramsi et al, 2006;Gutekunst et al, 2003) SrtA has been described as a regulator of pilus biosynthesis (Dramsi et al, 2006).…”

Section: Discussionmentioning

confidence: 99%

“…Following SDS-PAGE with gradient polyacrylamide gels, pilus structures form a ladder of bands corresponding to high-molecular-mass proteins (Dramsi et al, 2006;Gianfaldoni et al, 2007;Lauer et al, 2005;Mora et al, 2005;Rosini et al, 2006). Since Rga activates the expression of pilA, protein extracts of the three strains NEM316_pAT18, Drga_pAT18 and Drga_pATrga were size-separated by SDS-PAGE, and subsequently visualized by silver staining.…”

Section: Importance Of Rga For Pili Formationmentioning

confidence: 99%

Rga is a regulator of adherence and pilus formation in Streptococcus agalactiae

et al. 2011

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Streptococcus agalactiae is the leading cause of bacterial sepsis and meningitis in neonates and is also the causative agent of several serious infections in immunocompromised adults. S. agalactiae encounters multiple niches during an infection, suggesting that regulatory mechanisms control the expression of specific virulence factors in this bacterium. The present study describes the functional characterization of a gene from S. agalactiae, designated rga, which encodes a protein with significant similarity to members of the RofA-like protein (RALP) family of transcriptional regulators. After deletion of the rga gene in the genome of S. agalactiae, the mutant strain exhibited significantly reduced expression of the genes srr-1 and pilA, which encode a serine-rich repeat surface glycoprotein and a pilus protein, respectively, and moderately increased expression of the fbsA gene, which encodes a fibrinogen-binding protein. Electrophoretic mobility shift assays demonstrated specific DNA binding of purified Rga to the promoter regions of pilA and fbsA, suggesting that Rga directly controls pilA and fbsA. Adherence assays revealed significantly reduced binding of the Δrga mutant to epithelial HEp-2 cells and to immobilized human keratin 4, respectively. In contrast, the adherence of the Δrga mutant to A549 cells and its binding to human fibrinogen was significantly increased. Immunoblot and immunoelectron microscopy revealed that the quantity of pilus structures was significantly reduced in the Δrga mutant compared with the parental strain. The wild-type phenotype could be restored by plasmid-mediated expression of rga, demonstrating that the mutant phenotypes resulted from a loss of Rga function.

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“…All GBS isolates examined to date elaborate pili, long filamentous structures that protrude from the bacterial surface (5). Genome sequence information from many GBS isolates revealed three pilus islands, designated PI-1, -2a, and -2b (15).…”

mentioning

confidence: 99%

“…1). Applied to the Grampositive pathogen Streptococcus agalactiae, these approaches led to the identification of pilus genes that are critically important for the disease process but display variation among different isolates (5). Combining structural biology approaches with domain mapping of protective epitopes, Nuccitelli et al (3) string together six antigenic variants of the same functional unit into a single recombinant antigen that elicits antibody-mediated vaccine protection against all of S. agalactiae isolates examined.…”

mentioning

confidence: 99%