scholarly journals Purification and Three-Dimensional Electron Microscopy Structure of the Neisseria meningitidis Type IV Pilus Biogenesis Protein PilG

2007 ◽  
Vol 189 (17) ◽  
pp. 6389-6396 ◽  
Author(s):  
Richard F. Collins ◽  
Muhammad Saleem ◽  
Jeremy P. Derrick
Keyword(s):  
Electron Microscopy ◽  
Neisseria Meningitidis ◽  
Metal Ion ◽  
Polyacrylamide Gel Electrophoresis ◽  
Three Dimensional ◽  
Type Ii Secretion ◽  
Type Ii ◽  
Type Iv Pilus ◽  
Type Iv ◽  
Pilus Biogenesis

ABSTRACT Type IV pili are surface-exposed retractable fibers which play a key role in the pathogenesis of Neisseria meningitidis and other gram-negative pathogens. PilG is an integral inner membrane protein and a component of the type IV pilus biogenesis system. It is related by sequence to the extensive GspF family of secretory proteins, which are involved in type II secretion processes. PilG was overexpressed and purified from Escherichia coli membranes by detergent extraction and metal ion affinity chromatography. Analysis of the purified protein by perfluoro-octanoic acid polyacrylamide gel electrophoresis showed that PilG formed dimers and tetramers. A three-dimensional (3-D) electron microscopy structure of the PilG multimer was determined using single-particle averaging applied to samples visualized by negative staining. Symmetry analysis of the unsymmetrized 3-D volume provided further evidence that the PilG multimer is a tetramer. The reconstruction also revealed an asymmetric bilobed structure approximately 125 Å in length and 80 Å in width. The larger lobe within the structure was identified as the N terminus by location of Ni-nitrilotriacetic acid nanogold particles to the N-terminal polyhistidine tag. We propose that the smaller lobe corresponds to the periplasmic domain of the protein, with the narrower “waist” region being the transmembrane section. This constitutes the first report of a 3-D structure of a member of the GspF family and suggests a physical basis for the role of the protein in linking cytoplasmic and periplasmic protein components of the type II secretion and type IV pilus biogenesis systems.

scholarly journals Structure of an Essential Type IV Pilus Biogenesis Protein Provides Insights into Pilus and Type II Secretion Systems

2012 ◽  
Vol 419 (1-2) ◽  
pp. 110-124 ◽  
Author(s):  
Atsushi Yamagata ◽  
Ekaterina Milgotina ◽  
Karen Scanlon ◽  
Lisa Craig ◽  
John A. Tainer ◽  
...  
Keyword(s):  
Type Ii Secretion ◽  
Type Ii ◽  
Secretion Systems ◽  
Type Iv Pilus ◽  
Type Iv ◽  
Pilus Biogenesis

scholarly journals Interactions between the Lipoprotein PilP and the Secretin PilQ in Neisseria meningitidis

2007 ◽  
Vol 189 (15) ◽  
pp. 5716-5727 ◽  
Author(s):  
Seetha V. Balasingham ◽  
Richard F. Collins ◽  
Reza Assalkhou ◽  
Håvard Homberset ◽  
Stephan A. Frye ◽  
...  
Keyword(s):  
Neisseria Meningitidis ◽  
Specific Interaction ◽  
Three Dimensional ◽  
Middle Part ◽  
Dna Uptake ◽  
Type Iv ◽  
Pilus Biogenesis ◽  
Inner Membrane Protein ◽  
Mutant Phenotypes

ABSTRACT Neisseria meningitidis can be the causative agent of meningitis or septicemia. This bacterium expresses type IV pili, which mediate a variety of functions, including autoagglutination, twitching motility, biofilm formation, adherence, and DNA uptake during transformation. The secretin PilQ supports type IV pilus extrusion and retraction, but it also requires auxiliary proteins for its assembly and localization in the outer membrane. Here we have studied the physical properties of the lipoprotein PilP and examined its interaction with PilQ. We found that PilP was an inner membrane protein required for pilus expression and transformation, since pilP mutants were nonpiliated and noncompetent. These mutant phenotypes were restored by the expression of PilP in trans. The pilP gene is located upstream of pilQ, and analysis of their transcripts indicated that pilP and pilQ were cotranscribed. Furthermore, analysis of the level of PilQ expression in pilP mutants revealed greatly reduced amounts of PilQ only in the deletion mutant, exhibiting a polar effect on pilQ transcription. In vitro experiments using recombinant fragments of PilP and PilQ showed that the N-terminal region of PilP interacted with the middle part of the PilQ polypeptide. A three-dimensional reconstruction of the PilQ-PilP interacting complex was obtained at low resolution by transmission electron microscopy, and PilP was shown to localize around the cap region of the PilQ oligomer. These findings suggest a role for PilP in pilus biogenesis. Although PilQ does not need PilP for its stabilization or membrane localization, the specific interaction between these two proteins suggests that they might have another coordinated activity in pilus extrusion/retraction or related functions.

scholarly journals Type II Protein Secretion in Pseudomonas aeruginosa: the Pseudopilus Is a Multifibrillar and Adhesive Structure

2003 ◽  
Vol 185 (9) ◽  
pp. 2749-2758 ◽  
Author(s):  
Éric Durand ◽  
Alain Bernadac ◽  
Geneviève Ball ◽  
Andrée Lazdunski ◽  
James N. Sturgis ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Hydrolytic Enzymes ◽  
Macromolecular Complex ◽  
Type Ii Secretion ◽  
Type Ii ◽  
Secretion Systems ◽  
Type Iv Pilus ◽  
Type Iv ◽  
Type Iv Pilin

ABSTRACT The type II secretion pathway of Pseudomonas aeruginosa is involved in the extracellular release of various toxins and hydrolytic enzymes such as exotoxin A and elastase. This pathway requires the function of a macromolecular complex called the Xcp secreton. The Xcp secreton shares many features with the machinery involved in type IV pilus assembly. More specifically, it involves the function of five pilin-like proteins, the XcpT-X pseudopilins. We show that, upon overexpression, the XcpT pseudopilin can be assembled in a pilus, which we call a type II pseudopilus. Image analysis and filtering of electron micrographs indicated that these appendages are composed of individual fibrils assembled together in a bundle structure. Our observations thus revealed that XcpT has properties similar to those of type IV pilin subunits. Interestingly, the assembly of the type II pseudopilus is not exclusively dependent on the Xcp machinery but can be supported by other similar machineries, such as the Pil (type IV pilus) and Hxc (type II secretion) systems of P. aeruginosa. In addition, heterologous pseudopilins can be assembled by P. aeruginosa into a type II pseudopilus. Finally, we showed that assembly of the type II pseudopilus confers increased bacterial adhesive capabilities. These observations confirmed the ability of pseudopilins to form a pilus structure and raise questions with respect to their function in terms of secretion and adhesion, two crucial biological processes in the course of bacterial infections.

Architecture of the type II secretion and type IV pilus machineries

2010 ◽  
Vol 5 (8) ◽  
pp. 1203-1218 ◽  
Author(s):  
Melissa Ayers ◽  
P Lynne Howell ◽  
Lori L Burrows
Keyword(s):  
Type Ii Secretion ◽  
Type Ii ◽  
Type Iv Pilus ◽  
Type Iv

scholarly journals Type IV pilus biogenesis in Neisseria meningitidis: PilW is involved in a step occurring after pilus assembly, essential for fibre stability and function

2004 ◽  
Vol 55 (1) ◽  
pp. 54-64 ◽  
Author(s):  
Etienne Carbonnelle ◽  
Sophie Hélaine ◽  
Laure Prouvensier ◽  
Xavier Nassif ◽  
Vladimir Pelicic
Keyword(s):  
Neisseria Meningitidis ◽  
Type Iv Pilus ◽  
Type Iv ◽  
Pilus Biogenesis ◽  
And Function ◽  
Pilus Assembly

scholarly journals Roles of Putative Type II Secretion and Type IV Pilus Systems in the Virulence of Uropathogenic Escherichia coli

PLoS ONE ◽  
2009 ◽  
Vol 4 (3) ◽  
pp. e4752 ◽  
Author(s):  
Ritwij Kulkarni ◽  
Bijaya K. Dhakal ◽  
E. Susan Slechta ◽  
Zachary Kurtz ◽  
Matthew A. Mulvey ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Uropathogenic Escherichia Coli ◽  
Type Ii Secretion ◽  
Type Ii ◽  
Type Iv Pilus ◽  
Type Iv

Identification and initial characterization of a new pair of sibling sRNAs of Neisseria gonorrhoeae involved in type IV pilus biogenesis

Microbiology ◽  
2021 ◽  
Vol 167 (9) ◽  
Author(s):  
Marie Zachary ◽  
Susanne Bauer ◽  
Maximilian Klepsch ◽  
Katharina Wagler ◽  
Bruno Hüttel ◽  
...  
Keyword(s):  
Target Genes ◽  
Target Prediction ◽  
Type Iv Pilus ◽  
Content Type ◽  
Type Iv ◽  
Gene Expression Control ◽  
Initial Characterization ◽  
Pilus Biogenesis ◽  
Regulatory Rnas

Non-coding regulatory RNAs mediate post-transcriptional gene expression control by a variety of mechanisms relying mostly on base-pairing interactions with a target mRNA. Though a plethora of putative non-coding regulatory RNAs have been identified by global transcriptome analysis, knowledge about riboregulation in the pathogenic Neisseriae is still limited. Here we report the initial characterization of a pair of sRNAs of N. gonorrhoeae , TfpR1 and TfpR2, which exhibit a similar secondary structure and identical single-stranded seed regions, and therefore might be considered as sibling sRNAs. By combination of in silico target prediction and sRNA pulse expression followed by differential RNA sequencing we identified target genes of TfpR1 which are involved in type IV pilus biogenesis and DNA damage repair. We provide evidence that members of the TfpR1 regulon can also be targeted by the sibling TfpR2.

scholarly journals Structure and function of minor pilins of type IV pili

2019 ◽  
Vol 209 (3) ◽  
pp. 301-308 ◽  
Author(s):  
Theis Jacobsen ◽  
Benjamin Bardiaux ◽  
Olivera Francetic ◽  
Nadia Izadi-Pruneyre ◽  
Michael Nilges
Keyword(s):  
Pathogenic Bacteria ◽  
Type Iv Pili ◽  
Host Cells ◽  
Type Ii Secretion ◽  
Type Iv Pilus ◽  
Type Iv ◽  
Flexible Fibers ◽  
Multiple Copies ◽  
Species Specific ◽  
And Function

AbstractType IV pili are versatile and highly flexible fibers formed on the surface of many Gram-negative and Gram-positive bacteria. Virulence and infection rate of several pathogenic bacteria, such as Neisseria meningitidis and Pseudomonas aeruginosa, are strongly dependent on the presence of pili as they facilitate the adhesion of the bacteria to the host cell. Disruption of the interactions between the pili and the host cells by targeting proteins involved in this interaction could, therefore, be a treatment strategy. A type IV pilus is primarily composed of multiple copies of protein subunits called major pilins. Additional proteins, called minor pilins, are present in lower abundance, but are essential for the assembly of the pilus or for its specific functions. One class of minor pilins is required to initiate the formation of pili, and may form a complex similar to that identified in the related type II secretion system. Other, species-specific minor pilins in the type IV pilus system have been shown to promote additional functions such as DNA binding, aggregation and adherence. Here, we will review the structure and the function of the minor pilins from type IV pili.

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