scholarly journals Characterization of the Francisella tularensis subsp. novicida type IV pilus

Microbiology ◽  
2008 ◽  
Vol 154 (7) ◽  
pp. 2139-2150 ◽  
Author(s):  
Xhavit Zogaj ◽  
Subhra Chakraborty ◽  
Jirong Liu ◽  
David G. Thanassi ◽  
Karl E. Klose
Keyword(s):  
Francisella Tularensis ◽  
Type Iv Pilus ◽  
Tularensis Subsp ◽  
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 Identification and Characterization of a Novel Competence Gene,comC, Required for DNA Binding and Uptake inAcinetobacter sp. Strain BD413

1998 ◽  
Vol 180 (6) ◽  
pp. 1592-1595 ◽  
Author(s):  
Caroline Link ◽  
Sandra Eickernjäger ◽  
Dirk Porstendörfer ◽  
Beate Averhoff
Keyword(s):  
Electron Microscopy ◽  
Dna Binding ◽  
Natural Transformation ◽  
Leader Sequence ◽  
Wild Type ◽  
Type Iv Pilus ◽  
Competence Gene ◽  
Type Iv ◽  
Identification And Characterization

ABSTRACT A gene (comC) essential for natural transformation was identified in Acinetobacter sp. strain BD413. ComC has a typical leader sequence and is similar to different type IV pilus assembly factors. A comC mutant (T308) is not able to bind or take up DNA but exhibits a piliation phenotype indistinguishable from the transformation wild type as revealed by electron microscopy.

scholarly journals Characterization of type IV pilus genes in plant growth-promoting Pseudomonas putida WCS358.

1994 ◽  
Vol 176 (3) ◽  
pp. 642-650 ◽  
Author(s):  
A de Groot ◽  
I Heijnen ◽  
H de Cock ◽  
A Filloux ◽  
J Tommassen
Keyword(s):  
Plant Growth ◽  
Pseudomonas Putida ◽  
Type Iv Pilus ◽  
Type Iv ◽  
Plant Growth Promoting ◽  
Growth Promoting

scholarly journals Functional Analysis of PilT from the Toxic Cyanobacterium Microcystis aeruginosa PCC 7806

2006 ◽  
Vol 189 (5) ◽  
pp. 1689-1697 ◽  
Author(s):  
Kenlee Nakasugi ◽  
Ralitza Alexova ◽  
Charles J. Svenson ◽  
Brett A. Neilan
Keyword(s):  
Gene Transfer ◽  
Microcystis Aeruginosa ◽  
Structural Models ◽  
Toxin Gene ◽  
Dna Uptake ◽  
Type Iv Pilus ◽  
Type Iv ◽  
Critical Residues ◽  
Pcc 6803

ABSTRACT The evolution of the microcystin toxin gene cluster in phylogenetically distant cyanobacteria has been attributed to recombination, inactivation, and deletion events, although gene transfer may also be involved. Since the microcystin-producing Microcystis aeruginosa PCC 7806 is naturally transformable, we have initiated the characterization of its type IV pilus system, involved in DNA uptake in many bacteria, to provide a physiological focus for the influence of gene transfer in microcystin evolution. The type IV pilus genes pilA, pilB, pilC, and pilT were shown to be expressed in M. aeruginosa PCC 7806. The purified PilT protein yielded a maximal ATPase activity of 37.5 ± 1.8 nmol Pi min−1 mg protein−1, with a requirement for Mg2+. Heterologous expression indicated that it could complement the pilT mutant of Pseudomonas aeruginosa, but not that of the cyanobacterium Synechocystis sp. strain PCC 6803, which was unexpected. Differences in two critical residues between the M. aeruginosa PCC 7806 PilT (7806 PilT) and the Synechocystis sp. strain PCC 6803 PilT proteins affected their theoretical structural models, which may explain the nonfunctionality of 7806 PilT in its cyanobacterial counterpart. Screening of the pilT gene in toxic and nontoxic strains of Microcystis was also performed.

scholarly journals Characterization of a Novel Type IV Pilus Locus Encoded on the Large Plasmid of Locus of Enterocyte Effacement-Negative Shiga-Toxigenic Escherichia coli Strains That Are Virulent for Humans

2002 ◽  
Vol 70 (6) ◽  
pp. 3094-3100 ◽  
Author(s):  
Potjanee Srimanote ◽  
Adrienne W. Paton ◽  
James C. Paton
Keyword(s):  
Escherichia Coli ◽  
Gastrointestinal Disease ◽  
Large Plasmid ◽  
Type Iv Pilus ◽  
Upstream Gene ◽  
Type Iv ◽  
Uremic Syndrome ◽  
Enterocyte Effacement

ABSTRACT The majority of Shiga-toxigenic Escherichia coli (STEC) strains isolated from humans with gastrointestinal disease carry large (approximately 90-kb) plasmids. We have been analyzing the megaplasmid (designated pO113) from an O113:H21 STEC strain (98NK2). This strain lacks the locus for enterocyte effacement (LEE) and yet was responsible for an outbreak of hemolytic uremic syndrome. In the present study, we demonstrate that pO113 carries a novel type IV pilus biosynthesis locus (pil) related to those of the IncI plasmids R721, R64, and ColIb9. The pO113 pil locus consists of 11 closely linked genes (pilL through pilV) with an additional separately transcribed upstream gene (pilI). It directs the expression of long thin pili on the 98NK2 surface and the hemagglutination of guinea pig erythrocytes. We also demonstrate that pO113 can be transferred by conjugation. However, the type IV pilus encoded by pO113 does not appear to be involved in the adherence of 98NK2 to HEp-2 or Hct-8 cells in vitro. Homologues of the pO113 pil locus were present in several other LEE-negative STEC strains but not in LEE-positive STEC strains belonging to serogroup O26, O111, or O157.

scholarly journals CryoEM map of Pseudomonas aeruginosa PilQ enables structural characterization of TsaP

2020 ◽  
Author(s):  
Matthew McCallum ◽  
Stephanie Tammam ◽  
John L. Rubinstein ◽  
Lori L. Burrows ◽  
P. Lynne Howell
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Virulence ◽  
Twitching Motility ◽  
Type Iv Pilus ◽  
Natural Competence ◽  
Over Expression ◽  
Type Iv ◽  
Signal Cascade ◽  
Surface Sensing

ABSTRACTThe type IV pilus machinery is a multi-protein complex that polymerizes and depolymerizes a pilus fibre used for attachment, twitching motility, phage adsorption, natural competence, protein secretion, and surface-sensing. An outer membrane secretin pore is required for passage of the pilus fibre out of the cell. Herein, the structure of the tetradecameric secretin, PilQ, from the Pseudomonas aeruginosa type IVa pilus system was determined to 4.3 Å and 4.4 Å resolution in the presence and absence of C7 symmetric spokes, respectively. The heptameric spokes were found to be the two tandem C-terminal domains of TsaP. TsaP forms a belt around PilQ and while the protein is not essential for twitching motility, over-expression of TsaP triggers a signal cascade upstream of PilY1 leading to cyclic di-GMP up-regulation. These results resolve the identity of the spokes identified with Proteobacterial PilQ homologs and may reveal a new component of the surface-sensing cyclic di-GMP signal cascade.IMPACT STATEMENTThe type IV pilus is critical for bacterial virulence. The co-structure of the pilus secretin PilQ and TsaP is determined. Characterization of TsaP implicates it in surface-sensing signal transduction.

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