1
|
Ellison TJ, Ellison CK. DNA binding is rate-limiting for natural transformation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.06.597730. [PMID: 38895488 PMCID: PMC11185590 DOI: 10.1101/2024.06.06.597730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Bacteria take up environmental DNA using dynamic appendages called type IV pili (T4P) to elicit horizontal gene transfer in a process called natural transformation. Natural transformation is widespread amongst bacteria yet determining how different factors universally contribute to or limit this process across species has remained challenging. Here we show that Acinetobacter baylyi, the most naturally transformable species, is highly transformable due to its ability to robustly bind nonspecific DNA via a dedicated orphan minor pilin, FimT. We show that, compared to its homologues, A. baylyi FimT contains multiple positively charged residues that additively promote DNA binding efficiency. Expression of A. baylyi FimT in a closely related Acinetobacter pathogen is sufficient to substantially improve its capacity for natural transformation, demonstrating that T4P-DNA binding is a rate-limiting step in this process. These results demonstrate the importance of T4P-DNA binding efficiency in driving natural transformation, establishing a key factor limiting horizontal gene transfer.
Collapse
|
2
|
Bhattacharyya A, Banerjee G, Chattopadhyay P. Probable Role of Type IV Pili of Aeromonas hydrophila in Human Pathogenicity. Pathogens 2024; 13:365. [PMID: 38787217 PMCID: PMC11124393 DOI: 10.3390/pathogens13050365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 04/15/2024] [Accepted: 04/24/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Aeromonas hydrophila is a widely recognized broad-spectrum pathogen that primarily targets the gastrointestinal tract. Type IV pili (T4P) are proteinaceous nano-machines located on the bacterial cell surface, playing a crucial role in host colonization and infection. Regrettably, the T4P systems of A. hydrophila remain largely underexplored. METHODS A. hydrophila genomes with complete genome assembly and annotation reports up to 31 March 2023, were obtained from the NCBI Genome database or KEGG genome database, followed by a global search for T4P secretion system genes. Protein sequences of these manually curetted genes were used as secondary quarry for Synteny analysis. Protein-protein interaction analysis was performed by string analysis and in silico study of genomic islands. RESULTS We identified 27 orthologs of type IV pili (T4P) nano-machine components in A. hydrophila. These orthologs are primarily distributed across three operons: pilABCD, pilMNOPQ, and pilVWXY. While the first two operons are commonly found in all experimental genomes, the presence of the pilVWXY operon, coding for 11 orthologs, is reported here for the first time in A. hydrophila. Notably, the complete pilVWXY operon is absent in nonvirulent strains. A genomic islands study between a nonvirulent and hypervirulent strain also confirms absence of most of the genes coded by pilVWXY in nonvirulent strain. Interestingly, among the 51 experimental genomes analyzed, the pilVWXY operon was completely absent in 10 strains, most of which are categorized as nonvirulent; Conclusions: The distribution of two major type IV pili (T4P) nano-machines, PilABCDMNOPQ and PilVWXY, is reported here for the first time in A. hydrophila. Additionally, this study suggests a potential role for the PilVWXY nano-machine in establishing human disease.
Collapse
Affiliation(s)
- Agradip Bhattacharyya
- Raja Rammohun Roy Mahavidyalaya, Radhanagar, Nangulpara, Hooghly, West Bengal 712406, India;
| | - Goutam Banerjee
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | | |
Collapse
|
3
|
Hernández-Sánchez A, Páez-Pérez ED, Alfaro-Saldaña E, Olivares-Illana V, García-Meza JV. Understanding a Core Pilin of the Type IVa Pili of Acidithiobacillus thiooxidans, PilV. J Microbiol Biotechnol 2024; 34:527-537. [PMID: 38346803 PMCID: PMC11016768 DOI: 10.4014/jmb.2310.10033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/22/2023] [Accepted: 12/29/2023] [Indexed: 04/17/2024]
Abstract
Pilins are protein subunits of pili. The pilins of type IV pili (T4P) in pathogenic bacteria are well characterized, but anything is known about the T4P proteins in acidophilic chemolithoautotrophic microorganisms such as the genus Acidithiobacillus. The interest in T4P of A. thiooxidans is because of their possible role in cell recruitment and bacterial aggregation on the surface of minerals during biooxidation of sulfide minerals. In this study we present a successful ad hoc methodology for the heterologous expression and purification of extracellular proteins such as the minor pilin PilV of the T4P of A. thiooxidans, a pilin exposed to extreme conditions of acidity and high oxidation-reduction potentials, and that interact with metal sulfides in an environment rich in dissolved minerals. Once obtained, the model structure of A. thiooxidans PilV revealed the core basic architecture of T4P pilins. Because of the acidophilic condition, we carried out in silico characterization of the protonation status of acidic and basic residues of PilV in order to calculate the ionization state at specific pH values and evaluated their pH stability. Further biophysical characterization was done using UV-visible and fluorescence spectroscopy and the results showed that PilV remains soluble and stable even after exposure to significant changes of pH. PilV has a unique amino acid composition that exhibits acid stability, with significant biotechnology implications such as biooxidation of sulfide minerals. The biophysics profiles of PilV open new paradigms about resilient proteins and stimulate the study of other pilins from extremophiles.
Collapse
Affiliation(s)
- Araceli Hernández-Sánchez
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, Sierra Leona 550, San Luis Potosí, 78210, SLP, México
| | - Edgar D. Páez-Pérez
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, Sierra Leona 550, San Luis Potosí, 78210, SLP, México
| | - Elvia Alfaro-Saldaña
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, Sierra Leona 550, San Luis Potosí, 78210, SLP, México
| | - Vanesa Olivares-Illana
- Laboratorio de Interacciones Biomoleculares y Cáncer. Instituto de Física, Universidad Autónoma de San Luis Potosí, Av. Parque Chapultepec 1570, Privadas del Pedregal, San Luis Potosí, 78210, SLP, México
| | - J. Viridiana García-Meza
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, Sierra Leona 550, San Luis Potosí, 78210, SLP, México
| |
Collapse
|
4
|
Little JI, Singh PK, Zhao J, Dunn S, Matz H, Donnenberg MS. Type IV pili of Enterobacteriaceae species. EcoSal Plus 2024:eesp00032023. [PMID: 38294234 DOI: 10.1128/ecosalplus.esp-0003-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 12/01/2023] [Indexed: 02/01/2024]
Abstract
Type IV pili (T4Ps) are surface filaments widely distributed among bacteria and archaea. T4Ps are involved in many cellular functions and contribute to virulence in some species of bacteria. Due to the diversity of T4Ps, different properties have been observed for homologous proteins that make up T4Ps in various organisms. In this review, we highlight the essential components of T4Ps, their functions, and similarities to related systems. We emphasize the unique T4Ps of enteric pathogens within the Enterobacteriaceae family, which includes pathogenic strains of Escherichia coli and Salmonella. These include the bundle-forming pilus (BFP) of enteropathogenic E. coli (EPEC), longus (Lng) and colonization factor III (CFA/III) of enterotoxigenic E. coli (ETEC), T4P of Salmonella enterica serovar Typhi, Colonization Factor Citrobacter (CFC) of Citrobacter rodentium, T4P of Yersinia pseudotuberculosis, a ubiquitous T4P that was characterized in enterohemorrhagic E. coli (EHEC), and the R64 plasmid thin pilus. Finally, we highlight areas for further study.
Collapse
Affiliation(s)
- Janay I Little
- School of Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Pradip K Singh
- School of Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Jinlei Zhao
- School of Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Shakeera Dunn
- Internal Medicine Residency, Bayhealth Medical Center, Dover, Delaware, USA
| | - Hanover Matz
- Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | | |
Collapse
|
5
|
Pelicic V. Mechanism of assembly of type 4 filaments: everything you always wanted to know (but were afraid to ask). MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 36947586 DOI: 10.1099/mic.0.001311] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Type 4 filaments (T4F) are a superfamily of filamentous nanomachines - virtually ubiquitous in prokaryotes and functionally versatile - of which type 4 pili (T4P) are the defining member. T4F are polymers of type 4 pilins, assembled by conserved multi-protein machineries. They have long been an important topic for research because they are key virulence factors in numerous bacterial pathogens. Our poor understanding of the molecular mechanisms of T4F assembly is a serious hindrance to the design of anti-T4F therapeutics. This review attempts to shed light on the fundamental mechanistic principles at play in T4F assembly by focusing on similarities rather than differences between several (mostly bacterial) T4F. This holistic approach, complemented by the revolutionary ability of artificial intelligence to predict protein structures, led to an intriguing mechanistic model of T4F assembly.
Collapse
Affiliation(s)
- Vladimir Pelicic
- Laboratoire de Chimie Bactérienne, UMR 7283 CNRS/Aix-Marseille Université, Institut de Microbiologie de la Méditerranée, Marseille, France
| |
Collapse
|
6
|
Characterization of a glycan-binding complex of minor pilins completes the analysis of Streptococcus sanguinis type 4 pili subunits. Proc Natl Acad Sci U S A 2023; 120:e2216237120. [PMID: 36626560 PMCID: PMC9934059 DOI: 10.1073/pnas.2216237120] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Type 4 filaments (T4F)-of which type 4 pili (T4P) are the archetype-are a superfamily of nanomachines nearly ubiquitous in prokaryotes. T4F are polymers of one major pilin, which also contain minor pilins whose roles are often poorly understood. Here, we complete the structure/function analysis of the full set of T4P pilins in the opportunistic bacterial pathogen Streptococcus sanguinis. We determined the structure of the minor pilin PilA, which is unexpectedly similar to one of the subunits of a tip-located complex of four minor pilins, widely conserved in T4F. We found that PilA interacts and dramatically stabilizes the minor pilin PilC. We determined the structure of PilC, showing that it is a modular pilin with a lectin module binding a subset of glycans prevalent in the human glycome, the host of S. sanguinis. Altogether, our findings support a model whereby the minor pilins in S. sanguinis T4P form a tip-located complex promoting adhesion to various host receptors. This has general implications for T4F.
Collapse
|
7
|
Vahvelainen N, Bozkurt E, Maula T, Johansson A, Pöllänen MT, Ihalin R. Pilus PilA of the naturally competent HACEK group pathogen Aggregatibacter actinomycetemcomitans stimulates human leukocytes and interacts with both DNA and proinflammatory cytokines. Microb Pathog 2022; 173:105843. [DOI: 10.1016/j.micpath.2022.105843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 10/20/2022] [Accepted: 10/20/2022] [Indexed: 11/11/2022]
|
8
|
Ronish LA, Sidner B, Yu Y, Piepenbrink KH. Recognition of extracellular DNA by type IV pili promotes biofilm formation by Clostridioides difficile. J Biol Chem 2022; 298:102449. [PMID: 36064001 PMCID: PMC9556784 DOI: 10.1016/j.jbc.2022.102449] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 11/15/2022] Open
Abstract
Clostridioides difficile is a Gram-positive bacillus, which is a frequent cause of gastrointestinal infections triggered by the depletion of the gut microbiome. Because of the frequent recurrence of these infections after antibiotic treatment, mechanisms of C. difficile persistence and recurrence, including biofilm formation, are of increasing interest. Previously, our group and others found that type IV pili, filamentous helical appendages polymerized from protein subunits, promoted microcolony and biofilm formation in C. difficile. In Gram-negative bacteria, the ability of type IV pili to mediate bacterial self-association has been explained through interactions between the pili of adjacent cells, but type IV pili from several Gram-negative species are also required for natural competence through DNA uptake. Here, we report the ability of two C. difficile pilin subunits, PilJ and PilW, to bind to DNA in vitro, as well as the defects in biofilm formation in the pilJ and pilW gene-interruption mutants. Additionally, we have resolved the X-ray crystal structure of PilW, which we use to model possible structural mechanisms for the formation of C. difficile biofilm through interactions between type IV pili and the DNA of the extracellular matrix. Taken together, our results provide further insight into the relationship between type IV pilus function and biofilm formation in C. difficile and, more broadly, suggest that DNA recognition by type IV pili and related structures may have functional importance beyond DNA uptake for natural competence.
Collapse
Affiliation(s)
- Leslie A Ronish
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Ben Sidner
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Yafan Yu
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA; Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Kurt H Piepenbrink
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA; Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA; Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA; Nebraska Food for Health Center, University of Nebraska-Lincoln, Lincoln, Nebraska, USA; Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, Nebraska, USA.
| |
Collapse
|
9
|
Hughes-Games A, Davis SA, Hill DJ. Direct visualization of sequence-specific DNA binding by gonococcal type IV pili. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35920810 DOI: 10.1099/mic.0.001224] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Neisseria gonorrhoeae, the causative agent of gonorrhoea, is a major burden on global healthcare systems, with an estimated ~80-90 million new global cases annually. This burden is exacerbated by increasing levels of antimicrobial resistance, which has greatly limited viable antimicrobial therapies. Decreasing gonococcal drug susceptibility has been driven largely by accumulation of chromosomal resistance determinants, which can be acquired through natural transformation, whereby DNA in the extracellular milieu is imported into cells and incorporated into the genome by homologous recombination. N. gonorrhoeae possesses a specialized system for DNA uptake, which strongly biases transformation in favour of DNA from closely related bacteria by recognizing a 10-12 bp DNA uptake sequence (DUS) motif, which is highly overrepresented in their chromosomal DNA. This process relies on numerous proteins, including the DUS-specific receptor ComP, which assemble retractile protein filaments termed type IV pili (T4P) extending from the cell surface, and one model for neisserial DNA uptake proposes that these filaments bind DNA in a DUS-dependent manner before retracting to transport DNA into the periplasm. However, conflicting evidence indicates that elongated pilus filaments may not have such a direct role in DNA binding uptake as this model suggests. Here, we quantitatively measured DNA binding to gonococcal T4P fibres by directly visualizing binding complexes with confocal fluorescence microscopy in order to confirm the sequence-specific, comP-dependent DNA binding capacity of elongated T4P fibres. This supports the idea that pilus filaments could be responsible for initially capturing DNA in the first step of sequence-specific DNA uptake.
Collapse
Affiliation(s)
- Alex Hughes-Games
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK.,Bristol Centre for Functional Nanomaterials, HH Wills Physics Laboratory, University of Bristol, Bristol, UK.,School of Chemistry, University of Bristol, Bristol, UK
| | - Sean A Davis
- School of Chemistry, University of Bristol, Bristol, UK
| | - Darryl J Hill
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| |
Collapse
|
10
|
Abstract
Type IV pili (T4P) are retractable multifunctional nanofibers present on the surface of numerous bacterial and archaeal species. Their importance to microbiology is difficult to overstate. The scientific journey leading to our current understanding of T4P structure and function has included many innovative research milestones. Although multiple T4P reviews over the years have emphasized recent advances, we find that current reports often omit many of the landmark discoveries in this field. Here, we attempt to highlight chronologically the most important work on T4P, from the discovery of pili to the application of sophisticated contemporary methods, which has brought us to our current state of knowledge. As there remains much to learn about the complex machine that assembles and retracts T4P, we hope that this review will increase the interest of current researchers and inspire innovative progress.
Collapse
|
11
|
Zheng H, Huang Y, Liu P, Yan L, Zhou Y, Yang C, Wu Y, Qin J, Guo Y, Pei X, Guo Y, Cui Y, Liang W. Population genomics of the food-borne pathogen Vibrio fluvialis reveals lineage associated pathogenicity-related genetic elements. Microb Genom 2022; 8. [PMID: 35212619 PMCID: PMC8942032 DOI: 10.1099/mgen.0.000769] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Vibrio fluvialis is a food-borne pathogen with epidemic potential that causes cholera-like acute gastroenteritis and sometimes extraintestinal infections in humans. However, research on its genetic diversity and pathogenicity-related genetic elements based on whole genome sequences is lacking. In this study, we collected and sequenced 130 strains of V. fluvialis from 14 provinces of China, and also determined the susceptibility of 35 of the strains to 30 different antibiotics. Combined with 52 publicly available V. fluvialis genomes, we inferred the population structure and investigated the characteristics of pathogenicity-related factors. The V. fluvialis strains exhibited high levels of homologous recombination and were assigned to two major populations, VflPop1 and VflPop2, according to the different compositions of their gene pools. VflPop2 was subdivided into groups 2.1 and 2.2. Except for VflPop2.2, which consisted only of Asian strains, the strains in VflPop1 and VflPop2.1 were distributed in the Americas, Asia and Europe. Analysis of the pathogenicity potential of V. fluvialis showed that most of the identified virulence-related genes or gene clusters showed high prevalence in V. fluvialis, except for three mobile genetic elements: pBD146, ICEVflInd1 and MGIVflInd1, which were scattered in only a few strains. A total of 21 antimicrobial resistance genes were identified in the genomes of the 182 strains analysed in this study, and 19 (90%) of them were exclusively present in VflPop2. Notably, the tetracycline resistance-related gene tet(35) was present in 150 (95%) of the strains in VflPop2, and in only one (4%) strain in VflPop1, indicating it was population-specific. In total, 91% of the 35 selected strains showed resistance to cefazolin, indicating V. fluvialis has a high resistance rate to cefazolin. Among the 15 genomes that carried the previously reported drug resistance-related plasmid pBD146, 11 (73%) showed resistance to trimethoprim-sulfamethoxazole, which we inferred was related to the presence of the dfr6 gene in the plasmid. On the basis of the population genomics analysis, the genetic diversity, population structure and distribution of pathogenicity-related factors of V. fluvialis were delineated in this study. The results will provide further clues regarding the evolution and pathogenic mechanisms of V. fluvialis, and improve our knowledge for the prevention and control of this pathogen.
Collapse
Affiliation(s)
- Hongyuan Zheng
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Yuanming Huang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, PR China
| | - Ping Liu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, PR China
| | - Lin Yan
- National Center for Food Safety Risk Assessment, Beijing 100022, PR China
| | - Yanyan Zhou
- Center of Clinical Laboratory, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, PR China
| | - Chao Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Yarong Wu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Jingliang Qin
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Yan Guo
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Xiaoyan Pei
- National Center for Food Safety Risk Assessment, Beijing 100022, PR China
| | - Yunchang Guo
- National Center for Food Safety Risk Assessment, Beijing 100022, PR China
| | - Yujun Cui
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Weili Liang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, PR China
| |
Collapse
|
12
|
Oliveira V, Aschtgen MS, van Erp A, Henriques-Normark B, Muschiol S. The Role of Minor Pilins in Assembly and Function of the Competence Pilus of Streptococcus pneumoniae. Front Cell Infect Microbiol 2022; 11:808601. [PMID: 35004361 PMCID: PMC8727766 DOI: 10.3389/fcimb.2021.808601] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 11/30/2021] [Indexed: 12/03/2022] Open
Abstract
The remarkable genomic plasticity of Streptococcus pneumoniae largely depends on its ability to undergo natural genetic transformation. To take up extracellular DNA, S. pneumoniae assembles competence pili composed of the major pilin ComGC. In addition to ComGC, four minor pilins ComGD, E, F, and G are expressed during bacterial competence, but their role in pilus biogenesis and transformation is unknown. Here, using a combination of protein-protein interaction assays we show that all four proteins can directly interact with each other. Pneumococcal ComGG stabilizes the minor pilin ComGD and ComGF and can interact with and stabilize the major pilin ComGC, thus, deletion of ComGG abolishes competence pilus assembly. We further demonstrate that minor pilins are present in sheared pili fractions and find ComGF to be incorporated along the competence pilus by immunofluorescence and electron microscopy. Finally, mutants of the invariant Glu5 residue (E5), ComGDE5A or ComGEE5A, but not ComGFE5A, were severely impaired in pilus formation and function. Together, our results suggest that ComGG, lacking E5, is essential for competence pilus assembly and function, and plays a central role in connecting the pneumococcal minor pilins to ComGC.
Collapse
Affiliation(s)
- Vitor Oliveira
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | | | - Anke van Erp
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Birgitta Henriques-Normark
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden
| | - Sandra Muschiol
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden
| |
Collapse
|
13
|
Ellison CK, Whitfield GB, Brun YV. Type IV Pili: Dynamic Bacterial Nanomachines. FEMS Microbiol Rev 2021; 46:6425739. [PMID: 34788436 DOI: 10.1093/femsre/fuab053] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 11/08/2021] [Indexed: 01/19/2023] Open
Abstract
Bacteria and archaea rely on appendages called type IV pili (T4P) to participate in diverse behaviors including surface sensing, biofilm formation, virulence, protein secretion, and motility across surfaces. T4P are broadly distributed fibers that dynamically extend and retract, and this dynamic activity is essential for their function in broad processes. Despite the essentiality of dynamics in T4P function, little is known about the role of these dynamics and molecular mechanisms controlling them. Recent advances in microscopy have yielded insight into the role of T4P dynamics in their diverse functions and recent structural work has expanded what is known about the inner workings of the T4P motor. This review discusses recent progress in understanding the function, regulation, and mechanisms of T4P dynamics.
Collapse
Affiliation(s)
- Courtney K Ellison
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.,Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Gregory B Whitfield
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Yves V Brun
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| |
Collapse
|
14
|
Barnier JP, Meyer J, Kolappan S, Bouzinba-Ségard H, Gesbert G, Jamet A, Frapy E, Schönherr-Hellec S, Capel E, Virion Z, Dupuis M, Bille E, Morand P, Schmitt T, Bourdoulous S, Nassif X, Craig L, Coureuil M. The minor pilin PilV provides a conserved adhesion site throughout the antigenically variable meningococcal type IV pilus. Proc Natl Acad Sci U S A 2021; 118:e2109364118. [PMID: 34725157 PMCID: PMC8609321 DOI: 10.1073/pnas.2109364118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 09/16/2021] [Indexed: 01/14/2023] Open
Abstract
Neisseria meningitidis utilizes type IV pili (T4P) to adhere to and colonize host endothelial cells, a process at the heart of meningococcal invasive diseases leading to meningitis and sepsis. T4P are polymers of an antigenically variable major pilin building block, PilE, plus several core minor pilins that initiate pilus assembly and are thought to be located at the pilus tip. Adhesion of N. meningitidis to human endothelial cells requires both PilE and a conserved noncore minor pilin PilV, but the localization of PilV and its precise role in this process remains to be clarified. Here, we show that both PilE and PilV promote adhesion to endothelial vessels in vivo. The substantial adhesion defect observed for pilV mutants suggests it is the main adhesin. Consistent with this observation, superresolution microscopy showed the abundant distribution of PilV throughout the pilus. We determined the crystal structure of PilV and modeled it within the pilus filament. The small size of PilV causes it to be recessed relative to adjacent PilE subunits, which are dominated by a prominent hypervariable loop. Nonetheless, we identified a conserved surface-exposed adhesive loop on PilV by alanine scanning mutagenesis. Critically, antibodies directed against PilV inhibit N. meningitidis colonization of human skin grafts. These findings explain how N. meningitidis T4P undergo antigenic variation to evade the humoral immune response while maintaining their adhesive function and establish the potential of this highly conserved minor pilin as a vaccine and therapeutic target for the prevention and treatment of N. meningitidis infections.
Collapse
Affiliation(s)
- Jean-Philippe Barnier
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
- Service de Microbiologie, Assistance Publique-Hôpitaux de Paris, Centre-Université de Paris, Hôpital Necker Enfants-Malades, Paris 75015, France
| | - Julie Meyer
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| | - Subramania Kolappan
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 3Y6, Canada
| | - Haniaa Bouzinba-Ségard
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1016, CNRS UMR 8104, Institut Cochin, Paris 75014, France
| | - Gaël Gesbert
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| | - Anne Jamet
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
- Service de Microbiologie, Assistance Publique-Hôpitaux de Paris, Centre-Université de Paris, Hôpital Necker Enfants-Malades, Paris 75015, France
| | - Eric Frapy
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| | - Sophia Schönherr-Hellec
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| | - Elena Capel
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| | - Zoé Virion
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| | - Marion Dupuis
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| | - Emmanuelle Bille
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
- Service de Microbiologie, Assistance Publique-Hôpitaux de Paris, Centre-Université de Paris, Hôpital Necker Enfants-Malades, Paris 75015, France
| | - Philippe Morand
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
- Service de Bactériologie, Assistance Publique-Hôpitaux de Paris, Centre-Université de Paris, Hôpital Cochin, Paris 75014, France
| | - Taliah Schmitt
- Service de Chirurgie Reconstructrice et Plastique, Groupe Hospitalier Paris Saint-Joseph, Paris 75014, France
| | - Sandrine Bourdoulous
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1016, CNRS UMR 8104, Institut Cochin, Paris 75014, France
| | - Xavier Nassif
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
- Service de Microbiologie, Assistance Publique-Hôpitaux de Paris, Centre-Université de Paris, Hôpital Necker Enfants-Malades, Paris 75015, France
| | - Lisa Craig
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 3Y6, Canada;
| | - Mathieu Coureuil
- Faculté de Médecine, Université de Paris, Paris 75006, France;
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| |
Collapse
|
15
|
Custodio R, Ford RM, Ellison CJ, Liu G, Mickute G, Tang CM, Exley RM. Type VI secretion system killing by commensal Neisseria is influenced by expression of type four pili. eLife 2021; 10:63755. [PMID: 34232858 PMCID: PMC8263058 DOI: 10.7554/elife.63755] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 06/27/2021] [Indexed: 12/14/2022] Open
Abstract
Type VI Secretion Systems (T6SSs) are widespread in bacteria and can dictate the development and organisation of polymicrobial ecosystems by mediating contact dependent killing. In Neisseria species, including Neisseria cinerea a commensal of the human respiratory tract, interbacterial contacts are mediated by Type four pili (Tfp) which promote formation of aggregates and govern the spatial dynamics of growing Neisseria microcolonies. Here, we show that N. cinerea expresses a plasmid-encoded T6SS that is active and can limit growth of related pathogens. We explored the impact of Tfp on N. cinerea T6SS-dependent killing within a colony and show that pilus expression by a prey strain enhances susceptibility to T6SS compared to a non-piliated prey, by preventing segregation from a T6SS-wielding attacker. Our findings have important implications for understanding how spatial constraints during contact-dependent antagonism can shape the evolution of microbial communities.
Collapse
Affiliation(s)
- Rafael Custodio
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Rhian M Ford
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Cara J Ellison
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Guangyu Liu
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Gerda Mickute
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Christoph M Tang
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Rachel M Exley
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
16
|
Pili allow dominant marine cyanobacteria to avoid sinking and evade predation. Nat Commun 2021; 12:1857. [PMID: 33767153 PMCID: PMC7994388 DOI: 10.1038/s41467-021-22152-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 03/02/2021] [Indexed: 12/21/2022] Open
Abstract
How oligotrophic marine cyanobacteria position themselves in the water column is currently unknown. The current paradigm is that these organisms avoid sinking due to their reduced size and passive drift within currents. Here, we show that one in four picocyanobacteria encode a type IV pilus which allows these organisms to increase drag and remain suspended at optimal positions in the water column, as well as evade predation by grazers. The evolution of this sophisticated floatation mechanism in these purely planktonic streamlined microorganisms has important implications for our current understanding of microbial distribution in the oceans and predator-prey interactions which ultimately will need incorporating into future models of marine carbon flux dynamics.
Collapse
|
17
|
Barnier JP, Euphrasie D, Join-Lambert O, Audry M, Schonherr-Hellec S, Schmitt T, Bourdoulous S, Coureuil M, Nassif X, El Behi M. Type IV pilus retraction enables sustained bacteremia and plays a key role in the outcome of meningococcal sepsis in a humanized mouse model. PLoS Pathog 2021; 17:e1009299. [PMID: 33592056 PMCID: PMC7909687 DOI: 10.1371/journal.ppat.1009299] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 02/26/2021] [Accepted: 01/11/2021] [Indexed: 12/17/2022] Open
Abstract
Neisseria meningitidis (the meningococcus) remains a major cause of bacterial meningitis and fatal sepsis. This commensal bacterium of the human nasopharynx can cause invasive diseases when it leaves its niche and reaches the bloodstream. Blood-borne meningococci have the ability to adhere to human endothelial cells and rapidly colonize microvessels. This crucial step enables dissemination into tissues and promotes deregulated inflammation and coagulation, leading to extensive necrotic purpura in the most severe cases. Adhesion to blood vessels relies on type IV pili (TFP). These long filamentous structures are highly dynamic as they can rapidly elongate and retract by the antagonistic action of two ATPases, PilF and PilT. However, the consequences of TFP dynamics on the pathophysiology and the outcome of meningococcal sepsis in vivo have been poorly studied. Here, we show that human graft microvessels are replicative niches for meningococci, that seed the bloodstream and promote sustained bacteremia and lethality in a humanized mouse model. Intriguingly, although pilus-retraction deficient N. meningitidis strain (ΔpilT) efficiently colonizes human graft tissue, this mutant did not promote sustained bacteremia nor induce mouse lethality. This effect was not due to a decreased inflammatory response, nor defects in bacterial clearance by the innate immune system. Rather, TFP-retraction was necessary to promote the release of TFP-dependent contacts between bacteria and, in turn, the detachment from colonized microvessels. The resulting sustained bacteremia was directly correlated with lethality. Altogether, these results demonstrate that pilus retraction plays a key role in the occurrence and outcome of meningococcal sepsis by supporting sustained bacteremia. These findings open new perspectives on the role of circulating bacteria in the pathological alterations leading to lethal sepsis.
Collapse
Affiliation(s)
- Jean-Philippe Barnier
- Université de Paris, Faculté de Médecine, Paris, France
- Institut Necker Enfants-Malades, Inserm U1151, CNRS UMR 8253, Paris, France
- Service de microbiologie, Assistance Publique–Hôpitaux de Paris. Centre–Université de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Daniel Euphrasie
- Université de Paris, Faculté de Médecine, Paris, France
- Institut Necker Enfants-Malades, Inserm U1151, CNRS UMR 8253, Paris, France
| | - Olivier Join-Lambert
- Université de Paris, Faculté de Médecine, Paris, France
- Institut Necker Enfants-Malades, Inserm U1151, CNRS UMR 8253, Paris, France
- Service de microbiologie, Assistance Publique–Hôpitaux de Paris. Centre–Université de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Mathilde Audry
- Université de Paris, Faculté de Médecine, Paris, France
- Institut Necker Enfants-Malades, Inserm U1151, CNRS UMR 8253, Paris, France
| | - Sophia Schonherr-Hellec
- Université de Paris, Faculté de Médecine, Paris, France
- Institut Necker Enfants-Malades, Inserm U1151, CNRS UMR 8253, Paris, France
| | - Taliah Schmitt
- Service de chirurgie reconstructrice et plastique, Groupe Hospitalier Paris Saint-Joseph, Paris, France
| | - Sandrine Bourdoulous
- Université de Paris, Faculté de Médecine, Paris, France
- Institut Cochin, Inserm U1016, CNRS UMR 8104, Paris, France
| | - Mathieu Coureuil
- Université de Paris, Faculté de Médecine, Paris, France
- Institut Necker Enfants-Malades, Inserm U1151, CNRS UMR 8253, Paris, France
| | - Xavier Nassif
- Université de Paris, Faculté de Médecine, Paris, France
- Institut Necker Enfants-Malades, Inserm U1151, CNRS UMR 8253, Paris, France
- Service de microbiologie, Assistance Publique–Hôpitaux de Paris. Centre–Université de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Mohamed El Behi
- Université de Paris, Faculté de Médecine, Paris, France
- Institut Necker Enfants-Malades, Inserm U1151, CNRS UMR 8253, Paris, France
| |
Collapse
|
18
|
Wallner T, Pedroza L, Voigt K, Kaever V, Wilde A. The cyanobacterial phytochrome 2 regulates the expression of motility-related genes through the second messenger cyclic di-GMP. Photochem Photobiol Sci 2020; 19:631-643. [PMID: 32255440 DOI: 10.1039/c9pp00489k] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The cyanobacterial phytochrome Cph2 is a light-dependent diguanylate cyclase of the cyanobacterium Synechocystis 6803. Under blue light, Cph2-dependent increase in the cellular c-di-GMP concentration leads to inhibition of surface motility and enhanced flocculation of cells in liquid culture. However, the targets of second messenger signalling in this cyanobacterium and its mechanism of action remained unclear. Here, we determined the cellular concentrations of cAMP and c-di-GMP in wild-type and Δcph2 cells after exposure to blue and green light. Inactivation of cph2 completely abolished the blue-light dependent increase in c-di-GMP content. Therefore, a microarray analysis with blue-light grown wild-type and Δcph2 mutant cells was used to identify c-di-GMP dependent alterations in transcript accumulation. The increase in the c-di-GMP content alters expression of genes encoding putative cell appendages, minor pilins and components of chemotaxis systems. The mRNA encoding the minor pilins pilA5-pilA6 was negatively affected by high c-di-GMP content under blue light, whereas the minor pilin encoding operon pilA9-slr2019 accumulates under these conditions, suggesting opposing functions of the respective gene sets. Artificial overproduction of c-di-GMP leads to similar changes in minor pilin gene expression and supports previous findings that c-di-GMP is important for flocculation via the function of minor pilins. Mutational and gene expression analysis further suggest that SyCRP2, a CRP-like transcription factor, is involved in regulation of minor pilin and putative chaperone usher pili gene expression.
Collapse
Affiliation(s)
- Thomas Wallner
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, Freiburg, Germany.
| | - Laura Pedroza
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, Freiburg, Germany
| | - Karsten Voigt
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, Freiburg, Germany
| | - Volkhard Kaever
- Research Core Unit Metabolomics, Hannover Medical School, Hannover, Germany
| | - Annegret Wilde
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, Freiburg, Germany
| |
Collapse
|
19
|
Craig L, Forest KT, Maier B. Type IV pili: dynamics, biophysics and functional consequences. Nat Rev Microbiol 2020; 17:429-440. [PMID: 30988511 DOI: 10.1038/s41579-019-0195-4] [Citation(s) in RCA: 222] [Impact Index Per Article: 55.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The surfaces of many bacteria are decorated with long, exquisitely thin appendages called type IV pili (T4P), dynamic filaments that are rapidly polymerized and depolymerized from a pool of pilin subunits. Cycles of pilus extension, binding and retraction enable T4P to perform a phenomenally diverse array of functions, including twitching motility, DNA uptake and microcolony formation. On the basis of recent developments, a comprehensive understanding is emerging of the molecular architecture of the T4P machinery and the filament it builds, providing mechanistic insights into the assembly and retraction processes. Combined microbiological and biophysical approaches have revealed how T4P dynamics influence self-organization of bacteria, how bacteria respond to external stimuli to regulate T4P activity for directed movement, and the role of T4P retraction in surface sensing. In this Review, we discuss the T4P machine architecture and filament structure and present current molecular models for T4P dynamics, with a particular focus on recent insights into T4P retraction. We also discuss the functional consequences of T4P dynamics, which have important implications for bacterial lifestyle and pathogenesis.
Collapse
Affiliation(s)
- Lisa Craig
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.
| | - Katrina T Forest
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA.
| | - Berenike Maier
- Institute for Biological Physics, University of Cologne, Köln, Germany.
| |
Collapse
|
20
|
Crawshaw AD, Baslé A, Salgado PS. A practical overview of molecular replacement: Clostridioides difficile PilA1, a difficult case study. Acta Crystallogr D Struct Biol 2020; 76:261-271. [PMID: 32133990 PMCID: PMC7057214 DOI: 10.1107/s2059798320000467] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 01/14/2020] [Indexed: 12/02/2022] Open
Abstract
Many biologists are now routinely seeking to determine the three-dimensional structures of their proteins of choice, illustrating the importance of this knowledge, but also of the simplification and streamlining of structure-determination processes. Despite the fact that most software packages offer simple pipelines, for the non-expert navigating the outputs and understanding the key aspects can be daunting. Here, the structure determination of the type IV pili (TFP) protein PilA1 from Clostridioides difficile is used to illustrate the different steps involved, the key decision criteria and important considerations when using the most common pipelines and software. Molecular-replacement pipelines within CCP4i2 are presented to illustrate the more commonly used processes. Previous knowledge of the biology and structure of TFP pilins, particularly the presence of a long, N-terminal α-helix required for pilus formation, allowed informed decisions to be made during the structure-determination strategy. The PilA1 structure was finally successfully determined using ARCIMBOLDO and the ab initio MR strategy used is described.
Collapse
Affiliation(s)
- Adam D. Crawshaw
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, England
| | - Arnaud Baslé
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, England
| | - Paula S. Salgado
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, England
| |
Collapse
|
21
|
Jacobsen T, Bardiaux B, Francetic O, Izadi-Pruneyre N, Nilges M. Structure and function of minor pilins of type IV pili. Med Microbiol Immunol 2019; 209:301-308. [PMID: 31784891 PMCID: PMC7248040 DOI: 10.1007/s00430-019-00642-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 11/14/2019] [Indexed: 02/06/2023]
Abstract
Type 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.
Collapse
Affiliation(s)
- Theis Jacobsen
- Structural Bioinformatics Unit, Department of Structural Biology and Chemistry, C3BI, Institut Pasteur, CNRS UMR3528, CNRS USR3756, Paris, France.,Sorbonne Université, Complexité du Vivant, 75005, Paris, France
| | - Benjamin Bardiaux
- Structural Bioinformatics Unit, Department of Structural Biology and Chemistry, C3BI, Institut Pasteur, CNRS UMR3528, CNRS USR3756, Paris, France
| | - Olivera Francetic
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, Institut Pasteur, CNRS UMR3528, Paris, France
| | - Nadia Izadi-Pruneyre
- Structural Bioinformatics Unit, Department of Structural Biology and Chemistry, C3BI, Institut Pasteur, CNRS UMR3528, CNRS USR3756, Paris, France
| | - Michael Nilges
- Structural Bioinformatics Unit, Department of Structural Biology and Chemistry, C3BI, Institut Pasteur, CNRS UMR3528, CNRS USR3756, Paris, France.
| |
Collapse
|
22
|
Virion Z, Doly S, Saha K, Lambert M, Guillonneau F, Bied C, Duke RM, Rudd PM, Robbe-Masselot C, Nassif X, Coureuil M, Marullo S. Sialic acid mediated mechanical activation of β 2 adrenergic receptors by bacterial pili. Nat Commun 2019; 10:4752. [PMID: 31628314 PMCID: PMC6800425 DOI: 10.1038/s41467-019-12685-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 09/21/2019] [Indexed: 01/14/2023] Open
Abstract
Meningococcus utilizes β-arrestin selective activation of endothelial cell β2 adrenergic receptor (β2AR) to cause meningitis in humans. Molecular mechanisms of receptor activation by the pathogen and of its species selectivity remained elusive. We report that β2AR activation requires two asparagine-branched glycan chains with terminally exposed N-acetyl-neuraminic acid (sialic acid, Neu5Ac) residues located at a specific distance in its N-terminus, while being independent of surrounding amino-acid residues. Meningococcus triggers receptor signaling by exerting direct and hemodynamic-promoted traction forces on β2AR glycans. Similar activation is recapitulated with beads coated with Neu5Ac-binding lectins, submitted to mechanical stimulation. This previously unknown glycan-dependent mode of allosteric mechanical activation of a G protein-coupled receptor contributes to meningococcal species selectivity, since Neu5Ac is only abundant in humans due to the loss of CMAH, the enzyme converting Neu5Ac into N-glycolyl-neuraminic acid in other mammals. It represents an additional mechanism of evolutionary adaptation of a pathogen to its host.
Collapse
Affiliation(s)
- Zoe Virion
- Inserm, U1151, CNRS UMR 8253, Institut-Necker-Enfants-Malades, Université de Paris, Paris, France
| | - Stéphane Doly
- Inserm, U1016, CNRS UMR8104, Institut Cochin, Université de Paris, Paris, France
| | - Kusumika Saha
- Inserm, U1016, CNRS UMR8104, Institut Cochin, Université de Paris, Paris, France
| | - Mireille Lambert
- Inserm, U1016, CNRS UMR8104, Institut Cochin, Université de Paris, Paris, France
| | | | - Camille Bied
- Inserm, U1016, CNRS UMR8104, Institut Cochin, Université de Paris, Paris, France
| | - Rebecca M Duke
- NIBRT GlycoScience Group, NIBRT - The National Institute for Bioprocessing Research and Training, Blackrock, Co., Mount Merrion, Fosters Avenue, Dublin, Ireland
| | - Pauline M Rudd
- NIBRT GlycoScience Group, NIBRT - The National Institute for Bioprocessing Research and Training, Blackrock, Co., Mount Merrion, Fosters Avenue, Dublin, Ireland
| | - Catherine Robbe-Masselot
- CNRS, UMR 8576, Unité de Glycobiologie Structurale et Fonctionnelle (UGSF), Université Lille, 59000, Lille, France
| | - Xavier Nassif
- Inserm, U1151, CNRS UMR 8253, Institut-Necker-Enfants-Malades, Université de Paris, Paris, France.,Assistance Publique - Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Mathieu Coureuil
- Inserm, U1151, CNRS UMR 8253, Institut-Necker-Enfants-Malades, Université de Paris, Paris, France.
| | - Stefano Marullo
- Inserm, U1016, CNRS UMR8104, Institut Cochin, Université de Paris, Paris, France.
| |
Collapse
|
23
|
Kennouche P, Charles-Orszag A, Nishiguchi D, Goussard S, Imhaus AF, Dupré M, Chamot-Rooke J, Duménil G. Deep mutational scanning of the Neisseria meningitidis major pilin reveals the importance of pilus tip-mediated adhesion. EMBO J 2019; 38:e102145. [PMID: 31609039 DOI: 10.15252/embj.2019102145] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 09/10/2019] [Accepted: 09/12/2019] [Indexed: 11/09/2022] Open
Abstract
Type IV pili (TFP) are multifunctional micrometer-long filaments expressed at the surface of many prokaryotes. In Neisseria meningitidis, TFP are crucial for virulence. Indeed, these homopolymers of the major pilin PilE mediate interbacterial aggregation and adhesion to host cells. However, the mechanisms behind these functions remain unclear. Here, we simultaneously determined regions of PilE involved in pilus display, auto-aggregation, and adhesion by using deep mutational scanning and started mining this extensive functional map. For auto-aggregation, pili must reach a minimum length to allow pilus-pilus interactions through an electropositive cluster of residues centered around Lys140. For adhesion, results point to a key role for the tip of the pilus. Accordingly, purified pili interacting with host cells initially bind via their tip-located major pilin and then along their length. Overall, these results identify functional domains of PilE and support a direct role of the major pilin in TFP-dependent aggregation and adhesion.
Collapse
Affiliation(s)
- Paul Kennouche
- Pathogenesis of Vascular Infections Unit, INSERM, Institut Pasteur, Paris, France.,Université Paris Descartes, Paris, France
| | | | - Daiki Nishiguchi
- Pathogenesis of Vascular Infections Unit, INSERM, Institut Pasteur, Paris, France
| | - Sylvie Goussard
- Pathogenesis of Vascular Infections Unit, INSERM, Institut Pasteur, Paris, France
| | - Anne-Flore Imhaus
- Pathogenesis of Vascular Infections Unit, INSERM, Institut Pasteur, Paris, France
| | - Mathieu Dupré
- Institut Pasteur, CNRS USR 2000, Mass Spectrometry for Biology Unit, Paris, France
| | - Julia Chamot-Rooke
- Institut Pasteur, CNRS USR 2000, Mass Spectrometry for Biology Unit, Paris, France
| | - Guillaume Duménil
- Pathogenesis of Vascular Infections Unit, INSERM, Institut Pasteur, Paris, France
| |
Collapse
|
24
|
Chuang SK, Vrla GD, Fröhlich KS, Gitai Z. Surface association sensitizes Pseudomonas aeruginosa to quorum sensing. Nat Commun 2019; 10:4118. [PMID: 31511506 PMCID: PMC6739362 DOI: 10.1038/s41467-019-12153-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 08/19/2019] [Indexed: 11/09/2022] Open
Abstract
In the pathogen Pseudomonas aeruginosa, LasR is a quorum sensing (QS) master regulator that senses the concentration of secreted autoinducers as a proxy for bacterial cell density. Counterintuitively, previous studies showed that saturating amounts of the LasR ligand, 3OC12-HSL, fail to induce the full LasR regulon in low-density liquid cultures. Here we demonstrate that surface association, which is necessary for many of the same group behaviors as QS, promotes stronger QS responses. We show that lasR is upregulated upon surface association, and that surface-associated bacteria induce LasR targets more strongly in response to autoinducer than planktonic cultures. This increased sensitivity may be due to surface-dependent lasR induction initiating a positive feedback loop through the small RNA, Lrs1. The increased sensitivity of surface-associated cells to QS is affected by the type IV pilus (TFP) retraction motors and the minor pilins. The coupling of physical surface responses and chemical QS responses could enable these bacteria to trigger community behaviors more robustly when they are more beneficial.
Collapse
Affiliation(s)
- Sara K Chuang
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08540, USA
| | - Geoffrey D Vrla
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08540, USA
| | - Kathrin S Fröhlich
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08540, USA
- Department of Biology I, Microbiology, Ludwig-Maximilians-University Munich, D-82152, Martinsried, Germany
| | - Zemer Gitai
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08540, USA.
| |
Collapse
|
25
|
Gutierrez-Rodarte M, Kolappan S, Burrell BA, Craig L. The Vibrio cholerae minor pilin TcpB mediates uptake of the cholera toxin phage CTXφ. J Biol Chem 2019; 294:15698-15710. [PMID: 31471320 DOI: 10.1074/jbc.ra119.009980] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/27/2019] [Indexed: 12/13/2022] Open
Abstract
Virulent strains of the bacterial pathogen Vibrio cholerae cause the diarrheal disease cholera by releasing cholera toxin into the small intestine. V. cholerae acquired its cholera toxin genes by lysogenic infection with the filamentous bacteriophage CTXφ. CTXφ uses its minor coat protein pIII, located in multiple copies at the phage tip, to bind to the V. cholerae toxin-coregulated pilus (TCP). However, the molecular details of this interaction and the mechanism of phage internalization are not well-understood. The TCP filament is a polymer of major pilins, TcpA, and one or more minor pilin, TcpB. TCP are retractile, with both retraction and assembly initiated by TcpB. Consistent with these roles in pilus dynamics, we hypothesized that TcpB controls both binding and internalization of CTXφ. To test this hypothesis, we determined the crystal structure of the C-terminal half of TcpB and characterized its interactions with CTXφ pIII. We show that TcpB is a homotrimer in its crystallographic form as well as in solution and is present in multiple copies at the pilus tip, which likely facilitates polyvalent binding to pIII proteins at the phage tip. We further show that recombinant forms of TcpB and pIII interact in vitro, and both TcpB and anti-TcpB antibodies block CTXφ infection of V. cholerae Finally, we show that CTXφ uptake requires TcpB-mediated retraction. Our data support a model whereby CTXφ and TCP bind in a tip-to-tip orientation, allowing the phage to be drawn into the V. cholerae periplasm as an extension of the pilus filament.
Collapse
Affiliation(s)
- Miguel Gutierrez-Rodarte
- Molecular Biology and Biochemistry Department, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Subramania Kolappan
- Molecular Biology and Biochemistry Department, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Bailey A Burrell
- Molecular Biology and Biochemistry Department, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Lisa Craig
- Molecular Biology and Biochemistry Department, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| |
Collapse
|
26
|
Coureuil M, Jamet A, Bille E, Lécuyer H, Bourdoulous S, Nassif X. Molecular interactions between Neisseria meningitidis and its human host. Cell Microbiol 2019; 21:e13063. [PMID: 31167044 PMCID: PMC6899865 DOI: 10.1111/cmi.13063] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/21/2019] [Accepted: 05/30/2019] [Indexed: 02/06/2023]
Abstract
Neisseria meningitidis is a Gram‐negative bacterium that asymptomatically colonises the nasopharynx of humans. For an unknown reason, N. meningitidis can cross the nasopharyngeal barrier and invade the bloodstream where it becomes one of the most harmful extracellular bacterial pathogen. This infectious cycle involves the colonisation of two different environments. (a) In the nasopharynx, N. meningitidis grow on the top of mucus‐producing epithelial cells surrounded by a complex microbiota. To survive and grow in this challenging environment, the meningococcus expresses specific virulence factors such as polymorphic toxins and MDAΦ. (b) Meningococci have the ability to survive in the extra cellular fluids including blood and cerebrospinal fluid. The interaction of N. meningitidis with human endothelial cells leads to the formation of typical microcolonies that extend overtime and promote vascular injury, disseminated intravascular coagulation, and acute inflammation. In this review, we will focus on the interplay between N. meningitidis and these two different niches at the cellular and molecular level and discuss the use of inhibitors of piliation as a potent therapeutic approach.
Collapse
Affiliation(s)
- Mathieu Coureuil
- Inserm, Institut Necker Enfants Malades, U1151, Paris, France.,Université de Paris, UMR_S 1151, Paris, France.,CNRS, UMR 8253, Paris, France
| | - Anne Jamet
- Inserm, Institut Necker Enfants Malades, U1151, Paris, France.,Université de Paris, UMR_S 1151, Paris, France.,CNRS, UMR 8253, Paris, France.,Assistance Publique - Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Emmanuelle Bille
- Inserm, Institut Necker Enfants Malades, U1151, Paris, France.,Université de Paris, UMR_S 1151, Paris, France.,CNRS, UMR 8253, Paris, France.,Assistance Publique - Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Hervé Lécuyer
- Inserm, Institut Necker Enfants Malades, U1151, Paris, France.,Université de Paris, UMR_S 1151, Paris, France.,CNRS, UMR 8253, Paris, France.,Assistance Publique - Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Sandrine Bourdoulous
- Université de Paris, UMR_S 1151, Paris, France.,Inserm, U1016, Institut Cochin, Paris, France.,CNRS, UMR8104, Paris, France
| | - Xavier Nassif
- Inserm, Institut Necker Enfants Malades, U1151, Paris, France.,Université de Paris, UMR_S 1151, Paris, France.,CNRS, UMR 8253, Paris, France.,Assistance Publique - Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| |
Collapse
|
27
|
Abstract
Type IV pilus (T4P)-like systems have been identified in almost every major phylum of prokaryotic life. They include the type IVa pilus (T4aP), type II secretion system (T2SS), type IVb pilus (T4bP), Tad/Flp pilus, Com pilus, and archaeal flagellum (archaellum). These systems are used for adhesion, natural competence, phage adsorption, folded-protein secretion, surface sensing, swimming motility, and twitching motility. The T4aP allows for all of these functions except swimming and is therefore a good model system for understanding T4P-like systems. Recent structural analyses have revolutionized our understanding of how the T4aP machinery assembles and functions. Here we review the structure and function of the T4aP.
Collapse
|
28
|
Berry JL, Gurung I, Anonsen JH, Spielman I, Harper E, Hall AMJ, Goosens VJ, Raynaud C, Koomey M, Biais N, Matthews S, Pelicic V. Global biochemical and structural analysis of the type IV pilus from the Gram-positive bacterium Streptococcus sanguinis. J Biol Chem 2019; 294:6796-6808. [PMID: 30837269 PMCID: PMC6497953 DOI: 10.1074/jbc.ra118.006917] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/27/2019] [Indexed: 11/06/2022] Open
Abstract
Type IV pili (Tfp) are functionally versatile filaments, widespread in prokaryotes, that belong to a large class of filamentous nanomachines known as type IV filaments (Tff). Although Tfp have been extensively studied in several Gram-negative pathogens where they function as key virulence factors, many aspects of their biology remain poorly understood. Here, we performed a global biochemical and structural analysis of Tfp in a recently emerged Gram-positive model, Streptococcus sanguinis In particular, we focused on the five pilins and pilin-like proteins involved in Tfp biology in S. sanguinis We found that the two major pilins, PilE1 and PilE2, (i) follow widely conserved principles for processing by the prepilin peptidase PilD and for assembly into filaments; (ii) display only one of the post-translational modifications frequently found in pilins, i.e. a methylated N terminus; (iii) are found in the same heteropolymeric filaments; and (iv) are not functionally equivalent. The 3D structure of PilE1, solved by NMR, revealed a classical pilin-fold with a highly unusual flexible C terminus. Intriguingly, PilE1 more closely resembles pseudopilins forming shorter Tff than bona fide Tfp-forming major pilins, underlining the evolutionary relatedness among different Tff. Finally, we show that S. sanguinis Tfp contain a low abundance of three additional proteins processed by PilD, the minor pilins PilA, PilB, and PilC. These findings provide the first global biochemical and structural picture of a Gram-positive Tfp and have fundamental implications for our understanding of a widespread class of filamentous nanomachines.
Collapse
Affiliation(s)
- Jamie-Lee Berry
- From the Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Ishwori Gurung
- From the Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Jan Haug Anonsen
- the Department of Biological Sciences, Proteomics and Mass Spectrometry Unit, University of Oslo, 0371 Oslo, Norway.,the Department of Biological Sciences, Center for Integrative Microbial Evolution, University of Oslo, 0371 Oslo, Norway
| | - Ingrid Spielman
- the Department of Biology, Brooklyn College of the City University of New York, New York, New York 11210.,The Graduate Center of the City University of New York, New York, New York 10016, and
| | - Elliot Harper
- From the Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Alexander M J Hall
- From the Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Vivianne J Goosens
- From the Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Claire Raynaud
- From the Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Michael Koomey
- the Department of Biological Sciences, Center for Integrative Microbial Evolution, University of Oslo, 0371 Oslo, Norway
| | - Nicolas Biais
- the Department of Biology, Brooklyn College of the City University of New York, New York, New York 11210.,The Graduate Center of the City University of New York, New York, New York 10016, and
| | - Steve Matthews
- the Centre for Structural Biology, Imperial College London, London SW7 2AZ, United Kingdom
| | - Vladimir Pelicic
- From the Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom,
| |
Collapse
|
29
|
Luna Rico A, Zheng W, Petiot N, Egelman EH, Francetic O. Functional reconstitution of the type IVa pilus assembly system from enterohaemorrhagic Escherichia coli. Mol Microbiol 2019; 111:732-749. [PMID: 30561149 DOI: 10.1111/mmi.14188] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2018] [Indexed: 12/17/2022]
Abstract
Type 4a pili (T4aP) are long, thin and dynamic fibres displayed on the surface of diverse bacteria promoting adherence, motility and transport functions. Genomes of many Enterobacteriaceae contain conserved gene clusters encoding putative T4aP assembly systems. However, their expression has been observed only in few strains including Enterohaemorrhagic Escherichia coli (EHEC) and their inducers remain unknown. Here we used EHEC genomic DNA as a template to amplify and assemble an artificial operon composed of four gene clusters encoding 13 pilus assembly proteins. Controlled expressions of this operon in nonpathogenic E. coli strains led to efficient assembly of T4aP composed of the major pilin PpdD, as shown by shearing assays and immunofluorescence microscopy. When compared with PpdD pili assembled in a heterologous Klebsiella T2SS type 2 secretion system (T2SS) by using cryo-electron microscopy (cryoEM), these pili showed indistinguishable helical parameters, emphasizing that major pilins are the principal determinants of the fibre structure. Bacterial two-hybrid analysis identified several interactions of PpdD with T4aP assembly proteins, and with components of the T2SS that allow for heterologous fibre assembly. These studies lay ground for further characterization of the T4aP structure, function and biogenesis in enterobacteria.
Collapse
Affiliation(s)
- Areli Luna Rico
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, Institut Pasteur, CNRS UMR3528, 28 rue du Dr Roux, Paris, 75724, France.,Structural Bioinformatics Unit and NMR of Biomolecules Unit, Department of Structural Biology and Chemistry, Institut Pasteur, CNRS UMR3528, 28 rue du Dr Roux, Paris, 75724, France
| | - Weili Zheng
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, 22908, USA
| | - Nathalie Petiot
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, Institut Pasteur, CNRS UMR3528, 28 rue du Dr Roux, Paris, 75724, France
| | - Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, 22908, USA
| | - Olivera Francetic
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, Institut Pasteur, CNRS UMR3528, 28 rue du Dr Roux, Paris, 75724, France
| |
Collapse
|
30
|
Wang F, Coureuil M, Osinski T, Orlova A, Altindal T, Gesbert G, Nassif X, Egelman EH, Craig L. Cryoelectron Microscopy Reconstructions of the Pseudomonas aeruginosa and Neisseria gonorrhoeae Type IV Pili at Sub-nanometer Resolution. Structure 2018; 25:1423-1435.e4. [PMID: 28877506 DOI: 10.1016/j.str.2017.07.016] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 06/03/2017] [Accepted: 07/25/2017] [Indexed: 01/17/2023]
Abstract
We report here cryoelectron microscopy reconstructions of type IV pili (T4P) from two important human pathogens, Pseudomonas aeruginosa and Neisseria gonorrhoeae, at ∼ 8 and 5 Å resolution, respectively. The two structures reveal distinct arrangements of the pilin globular domains on the pilus surfaces, which impart different helical parameters, but similar packing of the conserved N-terminal α helices, α1, in the filament core. In contrast to the continuous α helix seen in the X-ray crystal structures of the P. aeruginosa and N. gonorrhoeae pilin subunits, α1 in the pilus filaments has a melted segment located between conserved helix-breaking residues Gly14 and Pro22, as seen for the Neisseria meningitidis T4P. Using mutagenesis we show that Pro22 is critical for pilus assembly, as are Thr2 and Glu5, which are positioned to interact in the hydrophobic filament core. These structures provide a framework for understanding T4P assembly, function, and biophysical properties.
Collapse
Affiliation(s)
- Fengbin Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Mathieu Coureuil
- Institut Necker-Enfants Malades, INSERM U1151, 14 Rue Maria Helena Vieira Da Silva, CS 61431, 75014 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, 15 Rue de l'École de Médecine, 75006 Paris, France
| | - Tomasz Osinski
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Albina Orlova
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Tuba Altindal
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Gaël Gesbert
- Institut Necker-Enfants Malades, INSERM U1151, 14 Rue Maria Helena Vieira Da Silva, CS 61431, 75014 Paris, France
| | - Xavier Nassif
- Institut Necker-Enfants Malades, INSERM U1151, 14 Rue Maria Helena Vieira Da Silva, CS 61431, 75014 Paris, France
| | - Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
| | - Lisa Craig
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.
| |
Collapse
|
31
|
Gurung I, Berry JL, Hall A, Pelicic V. Cloning-independent markerless gene editing in Streptococcus sanguinis: novel insights in type IV pilus biology. Nucleic Acids Res 2017; 45:e40. [PMID: 27903891 PMCID: PMC5389465 DOI: 10.1093/nar/gkw1177] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 11/14/2016] [Indexed: 11/14/2022] Open
Abstract
Streptococcus sanguinis, a naturally competent opportunistic human pathogen, is a Gram-positive workhorse for genomics. It has recently emerged as a model for the study of type IV pili (Tfp)—exceptionally widespread and important prokaryotic filaments. To enhance genetic manipulation of Streptococcus sanguinis, we have developed a cloning-independent methodology, which uses a counterselectable marker and allows sophisticated markerless gene editing in situ. We illustrate the utility of this methodology by answering several questions regarding Tfp biology by (i) deleting single or mutiple genes, (ii) altering specific bases in genes of interest, and (iii) engineering genes to encode proteins with appended affinity tags. We show that (i) the last six genes in the pil locus harbouring all the genes dedicated to Tfp biology play no role in piliation or Tfp-mediated motility, (ii) two highly conserved Asp residues are crucial for enzymatic activity of the prepilin peptidase PilD and (iii) that pilin subunits with a C-terminally appended hexa-histidine (6His) tag are still assembled into functional Tfp. The methodology for genetic manipulation we describe here should be broadly applicable.
Collapse
Affiliation(s)
- Ishwori Gurung
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Jamie-Lee Berry
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Alexander M. J. Hall
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Vladimir Pelicic
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
- To whom correspondence should be addressed. Tel: +44 20 7594 2080;
| |
Collapse
|
32
|
Arenas J, Tommassen J. Meningococcal Biofilm Formation: Let's Stick Together. Trends Microbiol 2017; 25:113-124. [DOI: 10.1016/j.tim.2016.09.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 09/13/2016] [Accepted: 09/16/2016] [Indexed: 11/26/2022]
|
33
|
Shu C, Xiao K, Yan Q, Sun X. Comparative Analysis of Type IV Pilin in Desulfuromonadales. Front Microbiol 2016; 7:2080. [PMID: 28066394 PMCID: PMC5174107 DOI: 10.3389/fmicb.2016.02080] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 12/08/2016] [Indexed: 12/24/2022] Open
Abstract
During anaerobic respiration, the bacteria Geobacter sulfurreducens can transfer electrons to extracellular electron accepters through its pilus. G. sulfurreducens pili have been reported to have metallic-like conductivity that is similar to doped organic semiconductors. To study the characteristics and origin of conductive pilin proteins found in the pilus structure, their genetic, structural, and phylogenetic properties were analyzed. The genetic relationships, and conserved structures and sequences that were obtained were used to predict the evolution of the pilins. Homologous genes that encode conductive pilin were found using PilFind and Cluster. Sequence characteristics and protein tertiary structures were analyzed with MAFFT and QUARK, respectively. The origin of conductive pilins was explored by building a phylogenetic tree. Truncation is a characteristic of conductive pilin. The structures of truncated pilins and their accompanying proteins were found to be similar to the N-terminal and C-terminal ends of full-length pilins respectively. The emergence of the truncated pilins can probably be ascribed to the evolutionary pressure of their extracellular electron transporting function. Genes encoding truncated pilins and proteins similar to the C-terminal of full-length pilins, which contain a group of consecutive anti-parallel beta-sheets, are adjacent in bacterial genomes. According to the genetic, structure, and phylogenetic analyses performed in this study, we inferred that the truncated pilins and their accompanying proteins probably evolved from full-length pilins by gene fission through duplication, degeneration, and separation. These findings provide new insights about the molecular mechanisms involved in long-range electron transport along the conductive pili of Geobacter species.
Collapse
Affiliation(s)
| | | | | | - Xiao Sun
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast UniversityNanjing, China
| |
Collapse
|
34
|
Ng D, Harn T, Altindal T, Kolappan S, Marles JM, Lala R, Spielman I, Gao Y, Hauke CA, Kovacikova G, Verjee Z, Taylor RK, Biais N, Craig L. The Vibrio cholerae Minor Pilin TcpB Initiates Assembly and Retraction of the Toxin-Coregulated Pilus. PLoS Pathog 2016; 12:e1006109. [PMID: 27992883 PMCID: PMC5207764 DOI: 10.1371/journal.ppat.1006109] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 01/03/2017] [Accepted: 12/02/2016] [Indexed: 01/03/2023] Open
Abstract
Type IV pilus (T4P) systems are complex molecular machines that polymerize major pilin proteins into thin filaments displayed on bacterial surfaces. Pilus functions require rapid extension and depolymerization of the pilus, powered by the assembly and retraction ATPases, respectively. A set of low abundance minor pilins influences pilus dynamics by unknown mechanisms. The Vibrio cholerae toxin-coregulated pilus (TCP) is among the simplest of the T4P systems, having a single minor pilin TcpB and lacking a retraction ATPase. Here we show that TcpB, like its homolog CofB, initiates pilus assembly. TcpB co-localizes with the pili but at extremely low levels, equivalent to one subunit per pilus. We used a micropillars assay to demonstrate that TCP are retractile despite the absence of a retraction ATPase, and that retraction relies on TcpB, as a V. cholerae tcpB Glu5Val mutant is fully piliated but does not induce micropillars movements. This mutant is impaired in TCP-mediated autoagglutination and TcpF secretion, consistent with retraction being required for these functions. We propose that TcpB initiates pilus retraction by incorporating into the growing pilus in a Glu5-dependent manner, which stalls assembly and triggers processive disassembly. These results provide a framework for understanding filament dynamics in more complex T4P systems and the closely related Type II secretion system. Bacterial pathogens utilize a number of highly complex and sophisticated molecular systems to colonize their hosts and alter them, creating customized niches in which to reproduce. One such system is the Type IV pilus system, made up of dozens of proteins that form a macromolecular machine to polymerize small pilin proteins into long thin filaments that are displayed on the bacterial surface. These pili have a remarkable array of functions that rely on their ability to (i) adhere to many substrates, including host cell surfaces, pili from nearby bacteria, DNA and bacterial viruses (bacteriophage), and (ii) to depolymerize or retract, which pulls the bacteria along mucosal surfaces, pulls them close together in protective aggregates, and can even draw in substrates like DNA and bacteriophage for nutrition and genetic variation. For most Type IV pilus systems, retraction is an energy-driven process facilitated by a retraction ATPase. We show here that in the simplest of the Type IV pilus systems, the Vibrio cholerae toxin-coregulated pilus, a pilin-like protein initiates pilus retraction by what appears to be mechanical rather than enzymatic means. Our results provide a framework for understanding more complex Type IV pili and the related Type II secretion systems, which represent targets for novel highly specific antibiotics.
Collapse
Affiliation(s)
- Dixon Ng
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Tony Harn
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Tuba Altindal
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Subramania Kolappan
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Jarrad M. Marles
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Rajan Lala
- Biology Department, Brooklyn College, City University of New York, Brooklyn, New York, United States of America
| | - Ingrid Spielman
- Biology Department, Brooklyn College, City University of New York, Brooklyn, New York, United States of America
| | - Yang Gao
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Caitlyn A. Hauke
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Gabriela Kovacikova
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Zia Verjee
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Ronald K. Taylor
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Nicolas Biais
- Biology Department, Brooklyn College, City University of New York, Brooklyn, New York, United States of America
- Graduate Center, City University of New York, Brooklyn, New York, United States of America
- * E-mail: (LC); (NB)
| | - Lisa Craig
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
- * E-mail: (LC); (NB)
| |
Collapse
|
35
|
Effects of tcpB Mutations on Biogenesis and Function of the Toxin-Coregulated Pilus, the Type IVb Pilus of Vibrio cholerae. J Bacteriol 2016; 198:2818-28. [PMID: 27481929 DOI: 10.1128/jb.00309-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 07/23/2016] [Indexed: 02/05/2023] Open
Abstract
UNLABELLED Vibrio cholerae is the etiological agent of the acute intestinal disorder cholera. The toxin-coregulated pilus (TCP), a type IVb pilus, is an essential virulence factor of V. cholerae Recent work has shown that TcpB is a large minor pilin encoded within the tcp operon. TcpB contributes to efficient pilus formation and is essential for all TCP functions. Here, we have initiated a detailed targeted mutagenesis approach to further characterize this salient TCP component. We have identified (thus far) 20 residues of TcpB which affect either the steady-state level of TcpB or alter one or more TCP functions. This study provides a solid framework for further understanding of the complex role of TcpB and will be of use upon determination of the crystal structure of TcpB or related minor pilin orthologs of type IVb pilus systems. IMPORTANCE Type IV pili, such as the toxin-coregulated pilus (TCP) in V. cholerae, are bacterial appendages that often act as essential virulence factors. Minor pilins, like TcpB, of these pili systems often play integral roles in pilus assembly and function. In this study, we have generated mutations in tcpB to determine residues of importance for TCP stability and function. Combined with a predicted tertiary structure, characterization of these mutants allows us to better understand critical residues in TcpB and the role they may play in the mechanisms underlying minor pilin functions.
Collapse
|
36
|
Karuppiah V, Thistlethwaite A, Derrick JP. Structures of type IV pilins from Thermus thermophilus demonstrate similarities with type II secretion system pseudopilins. J Struct Biol 2016; 196:375-384. [PMID: 27612581 PMCID: PMC5131608 DOI: 10.1016/j.jsb.2016.08.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 08/25/2016] [Accepted: 08/29/2016] [Indexed: 11/30/2022]
Abstract
Type IV pilins are proteins which form polymers that extend from the surface of the bacterial cell; they are involved in mediating a wide variety of functions, including adhesion, motility and natural competence. Here we describe the determination of the crystal structures of three type IVa pilins proteins from the thermophile Thermus thermophilus. They form part of a cluster of pilus-like proteins within the genome; our results show that one, Tt1222, is very closely related to the main structural type IV pilin, PilA4. The other two, Tt1218 and Tt1219, also adopt canonical pilin-like folds but, interestingly, are most closely related to the structures of the type II secretion system pseudopilins, EpsI/GspI and XcpW/GspJ. GspI and GspJ have been shown to form a complex with another pseudopilin, GspK, and this heterotrimeric complex is known to play a key role in initiating assembly of a pseudopilus which is thought to drive the secretion process. The structural similarity of Tt1218 and Tt1219 to GspI and GspJ suggests that they might work in a similar way, to deliver functions associated with type IV pili in T. thermophilus, such as natural competence.
Collapse
Affiliation(s)
- Vijaykumar Karuppiah
- Michael Smith Building, Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, UK
| | - Angela Thistlethwaite
- Michael Smith Building, Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, UK
| | - Jeremy P Derrick
- Michael Smith Building, Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, UK.
| |
Collapse
|
37
|
Berry JL, Xu Y, Ward PN, Lea SM, Matthews SJ, Pelicic V. A Comparative Structure/Function Analysis of Two Type IV Pilin DNA Receptors Defines a Novel Mode of DNA Binding. Structure 2016; 24:926-34. [PMID: 27161979 PMCID: PMC4906244 DOI: 10.1016/j.str.2016.04.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 03/19/2016] [Accepted: 04/04/2016] [Indexed: 11/29/2022]
Abstract
DNA transformation is a widespread process allowing bacteria to capture free DNA by using filamentous nano-machines composed of type IV pilins. These proteins can act as DNA receptors as demonstrated by the finding that Neisseria meningitidis ComP minor pilin has intrinsic DNA-binding ability. ComP binds DNA better when it contains the DNA-uptake sequence (DUS) motif abundant in this species genome, playing a role in its trademark ability to selectively take up its own DNA. Here, we report high-resolution structures for meningococcal ComP and Neisseria subflava ComPsub, which recognize different DUS motifs. We show that they are structurally identical type IV pilins that pack readily into filament models and display a unique DD region delimited by two disulfide bonds. Functional analysis of ComPsub defines a new mode of DNA binding involving the DD region, adapted for exported DNA receptors.
Collapse
Affiliation(s)
- Jamie-Lee Berry
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Yingqi Xu
- Centre for Structural Biology, Imperial College London, London SW7 2AZ, UK
| | - Philip N Ward
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Susan M Lea
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Stephen J Matthews
- Centre for Structural Biology, Imperial College London, London SW7 2AZ, UK.
| | - Vladimir Pelicic
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK.
| |
Collapse
|
38
|
Kawahara K, Oki H, Fukakusa S, Yoshida T, Imai T, Maruno T, Kobayashi Y, Motooka D, Iida T, Ohkubo T, Nakamura S. Homo-trimeric Structure of the Type IVb Minor Pilin CofB Suggests Mechanism of CFA/III Pilus Assembly in Human Enterotoxigenic Escherichia coli. J Mol Biol 2016; 428:1209-1226. [PMID: 26876601 DOI: 10.1016/j.jmb.2016.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/30/2016] [Accepted: 02/03/2016] [Indexed: 11/18/2022]
Abstract
In gram-negative bacteria, the assembly of type IV pilus (T4P) and the evolutionally related pseudopilus of type II secretion system involves specialized structural proteins called pilins and pseudopilins, respectively, and is dynamically regulated to promote bacterial pathogenesis. Previous studies have suggested that a structural "tip"-like hetero-complex formed through the interaction of at least three minor (pseudo) pilins plays an important role in this process, while some members of the pathogenic type IVb subfamily are known to have only one such minor pilin subunit whose function is still unknown. Here, we determined the crystal structure of the type IVb minor pilin CofB of colonization factor antigen/III from human enterotoxigenic Escherichia coli at 1.88-Å resolution. The crystal structure, in conjunction with physicochemical analysis in solution, reveals a symmetrical homo-trimeric arrangement distinct from the hetero-complexes of minor (pseudo) pilins observed in other T4P and type II secretion systems. Each CofB monomer adopts a unique three-domain architecture, in which the C-terminal β-sheet-rich lectin domain can effectively initiate trimer association of its pilin-like N-terminal domain through extensive hydrophobic interactions followed by domain swapping at the central hinge-like domain. Deletion of cofB produces a phenotype with no detectable pili formation on the cell surface, while molecular modeling indicates that the characteristic homo-trimeric structure of CofB is well situated at the pilus tip of colonization factor antigen/III formed by the major pilin CofA, suggesting a role for the minor pilin in the efficient initiation of T4P assembly.
Collapse
Affiliation(s)
- Kazuki Kawahara
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Hiroya Oki
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shunsuke Fukakusa
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takuya Yoshida
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tomoya Imai
- Research Institute for Sustainable Humanosphere (RISH), Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Takahiro Maruno
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yuji Kobayashi
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Daisuke Motooka
- Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tetsuya Iida
- Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tadayasu Ohkubo
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shota Nakamura
- Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| |
Collapse
|
39
|
BfpI, BfpJ, and BfpK Minor Pilins Are Important for the Function and Biogenesis of Bundle-Forming Pili Expressed by Enteropathogenic Escherichia coli. J Bacteriol 2015; 198:846-56. [PMID: 26712935 PMCID: PMC4810605 DOI: 10.1128/jb.00818-15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 12/17/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Enteropathogenic Escherichia coli (EPEC) remains a significant cause of infant diarrheal illness and associated morbidity and mortality in developing countries. EPEC strains are characterized by their ability to colonize the small intestines of their hosts by a multistep program involving initial loose attachment to intestinal epithelial cells followed by an intimate adhesion phase. The initial loose interaction of typical EPEC with host intestinal cells is mediated by bundle-forming pili (BFP). BFP are type 4b pili (T4bP) based on structural and functional properties shared with T4bP expressed by other bacteria. The major structural subunit of BFP is called bundlin, a T4b pilin expressed from the bfpA gene in the BFP operon, which contains three additional genes that encode the pilin-like proteins BfpI, BfpJ, and BfpK. In this study, we show that, in the absence of the BFP retraction ATPase (BfpF), BfpI, BfpJ, and BfpK are dispensable for BFP biogenesis. We also demonstrate that these three minor pilins are incorporated along with bundlin into the BFP filament and contribute to its structural integrity and host cell adhesive properties. The results confirm that previous findings in T4aP systems can be extended to a model T4bP such as BFP. IMPORTANCE Bundle-forming pili contribute to the host colonization strategy of enteropathogenic Escherichia coli. The studies described here investigate the role for three minor pilin subunits in the structure and function of BFP in EPEC. The studies also suggest that these subunits could be antigens for vaccine development.
Collapse
|
40
|
Sistrom M, Park D, O’Brien HE, Wang Z, Guttman DS, Townsend JP, Turner PE. Genomic and Gene-Expression Comparisons among Phage-Resistant Type-IV Pilus Mutants of Pseudomonas syringae pathovar phaseolicola. PLoS One 2015; 10:e0144514. [PMID: 26670219 PMCID: PMC4687649 DOI: 10.1371/journal.pone.0144514] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 11/19/2015] [Indexed: 11/18/2022] Open
Abstract
Pseudomonas syringae pv. phaseolicola (Pph) is a significant bacterial pathogen of agricultural crops, and phage Φ6 and other members of the dsRNA virus family Cystoviridae undergo lytic (virulent) infection of Pph, using the type IV pilus as the initial site of cellular attachment. Despite the popularity of Pph/phage Φ6 as a model system in evolutionary biology, Pph resistance to phage Φ6 remains poorly characterized. To investigate differences between phage Φ6 resistant Pph strains, we examined genomic and gene expression variation among three bacterial genotypes that differ in the number of type IV pili expressed per cell: ordinary (wild-type), non-piliated, and super-piliated. Genome sequencing of non-piliated and super-piliated Pph identified few mutations that separate these genotypes from wild type Pph--and none present in genes known to be directly involved in type IV pilus expression. Expression analysis revealed that 81.1% of gene ontology (GO) terms up-regulated in the non-piliated strain were down-regulated in the super-piliated strain. This differential expression is particularly prevalent in genes associated with respiration--specifically genes in the tricarboxylic acid cycle (TCA) cycle, aerobic respiration, and acetyl-CoA metabolism. The expression patterns of the TCA pathway appear to be generally up and down-regulated, in non-piliated and super-piliated Pph respectively. As pilus retraction is mediated by an ATP motor, loss of retraction ability might lead to a lower energy draw on the bacterial cell, leading to a different energy balance than wild type. The lower metabolic rate of the super-piliated strain is potentially a result of its loss of ability to retract.
Collapse
Affiliation(s)
- Mark Sistrom
- School of Natural Sciences, University of California Merced, Merced, 95343, CA, United States of America
- * E-mail:
| | - Derek Park
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, United States of America
| | - Heath E. O’Brien
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
| | - Zheng Wang
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, United States of America
| | - David S. Guttman
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Ontario, M5S 3B2, Canada
| | - Jeffrey P. Townsend
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, United States of America
- Department of Biostatistics, Yale School of Public Health, New Haven, CT 06520, United States of America
- Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520, United States of America
- Program in Microbiology, Yale University, New Haven, CT 06520, United States of America
| | - Paul E. Turner
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, United States of America
- Program in Microbiology, Yale University, New Haven, CT 06520, United States of America
| |
Collapse
|
41
|
Nguyen Y, Harvey H, Sugiman-Marangos S, Bell SD, Buensuceso RNC, Junop MS, Burrows LL. Structural and functional studies of the Pseudomonas aeruginosa minor pilin, PilE. J Biol Chem 2015; 290:26856-65. [PMID: 26359492 PMCID: PMC4646338 DOI: 10.1074/jbc.m115.683334] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 09/04/2015] [Indexed: 11/06/2022] Open
Abstract
Many bacterial pathogens, including Pseudomonas aeruginosa, use type IVa pili (T4aP) for attachment and twitching motility. T4aP are composed primarily of major pilin subunits, which are repeatedly assembled and disassembled to mediate function. A group of pilin-like proteins, the minor pilins FimU and PilVWXE, prime pilus assembly and are incorporated into the pilus. We showed previously that minor pilin PilE depends on the putative priming subcomplex PilVWX and the non-pilin protein PilY1 for incorporation into pili, and that with FimU, PilE may couple the priming subcomplex to the major pilin PilA, allowing for efficient pilus assembly. Here we provide further support for this model, showing interaction of PilE with other minor pilins and the major pilin. A 1.25 Å crystal structure of PilEΔ1-28 shows a typical type IV pilin fold, demonstrating how it may be incorporated into the pilus. Despite limited sequence identity, PilE is structurally similar to Neisseria meningitidis minor pilins PilXNm and PilVNm, recently suggested via characterization of mCherry fusions to modulate pilus assembly from within the periplasm. A P. aeruginosa PilE-mCherry fusion failed to complement twitching motility or piliation of a pilE mutant. However, in a retraction-deficient strain where surface piliation depends solely on PilE, the fusion construct restored some surface piliation. PilE-mCherry was present in sheared surface fractions, suggesting that it was incorporated into pili. Together, these data provide evidence that PilE, the sole P. aeruginosa equivalent of PilXNm and PilVNm, likely connects a priming subcomplex to the major pilin, promoting efficient assembly of T4aP.
Collapse
Affiliation(s)
- Ylan Nguyen
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
| | - Hanjeong Harvey
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
| | - Seiji Sugiman-Marangos
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
| | - Stephanie D Bell
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
| | - Ryan N C Buensuceso
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
| | - Murray S Junop
- the Department of Biochemistry, Western University, London, Ontario N6A 3K7, Canada
| | - Lori L Burrows
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1 and
| |
Collapse
|
42
|
Kolappan S, Ng D, Yang G, Harn T, Craig L. Crystal Structure of the Minor Pilin CofB, the Initiator of CFA/III Pilus Assembly in Enterotoxigenic Escherichia coli. J Biol Chem 2015; 290:25805-18. [PMID: 26324721 DOI: 10.1074/jbc.m115.676106] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Indexed: 01/04/2023] Open
Abstract
Type IV pili are extracellular polymers of the major pilin subunit. These subunits are held together in the pilus filament by hydrophobic interactions among their N-terminal α-helices, which also anchor the pilin subunits in the inner membrane prior to pilus assembly. Type IV pilus assembly involves a conserved group of proteins that span the envelope of Gram-negative bacteria. Among these is a set of minor pilins, so named because they share their hydrophobic N-terminal polymerization/membrane anchor segment with the major pilins but are much less abundant. Minor pilins influence pilus assembly and retraction, but their precise functions are not well defined. The Type IV pilus systems of enterotoxigenic Escherichia coli and Vibrio cholerae are among the simplest of Type IV pilus systems and possess only a single minor pilin. Here we show that the enterotoxigenic E. coli minor pilins CofB and LngB are required for assembly of their respective Type IV pili, CFA/III and Longus. Low levels of the minor pilins are optimal for pilus assembly, and CofB can be detected in the pilus fraction. We solved the 2.0 Å crystal structure of N-terminally truncated CofB, revealing a pilin-like protein with an extended C-terminal region composed of two discrete domains connected by flexible linkers. The C-terminal region is required for CofB to initiate pilus assembly. We propose a model for CofB-initiated pilus assembly with implications for understanding filament growth in more complex Type IV pilus systems as well as the related Type II secretion system.
Collapse
Affiliation(s)
- Subramania Kolappan
- From the Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Dixon Ng
- From the Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Guixiang Yang
- From the Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Tony Harn
- From the Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Lisa Craig
- From the Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| |
Collapse
|
43
|
Dewenter L, Volkmann TE, Maier B. Oxygen governs gonococcal microcolony stability by enhancing the interaction force between type IV pili. Integr Biol (Camb) 2015; 7:1161-70. [PMID: 25892255 DOI: 10.1039/c5ib00018a] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The formation of small bacterial clusters, called microcolonies, is the first step towards the formation of bacterial biofilms. The human pathogen Neisseria gonorrhoeae requires type IV pili (T4P) for microcolony formation and for surface motility. Here, we investigated the effect of oxygen on the dynamics of microcolony formation. We found that an oxygen concentration exceeding 3 μM is required for formation and maintenance of microcolonies. Depletion of proton motive force triggers microcolony disassembly. Disassembly of microcolonies is actively driven by T4P retraction. Using laser tweezers we showed that under aerobic conditions T4P-T4P interaction forces exceed 50 pN. Under anaerobic conditions T4P-T4P interaction is severely inhibited. We conclude that oxygen is required for gonococcal microcolony formation by enhancing pilus-pilus interaction.
Collapse
Affiliation(s)
- Lena Dewenter
- Department of Physics, Universität zu Köln, Köln, Germany.
| | | | | |
Collapse
|
44
|
Affiliation(s)
- Alain Filloux
- Alain Filloux, MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London SW7 2AZ, UK; E-mail:
| |
Collapse
|
45
|
Gorgel M, Ulstrup JJ, Bøggild A, Jones NC, Hoffmann SV, Nissen P, Boesen T. High-resolution structure of a type IV pilin from the metal-reducing bacterium Shewanella oneidensis. BMC STRUCTURAL BIOLOGY 2015; 15:4. [PMID: 25886849 PMCID: PMC4376143 DOI: 10.1186/s12900-015-0031-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 02/02/2015] [Indexed: 11/10/2022]
Abstract
Background Type IV pili are widely expressed among Gram-negative bacteria, where they are involved in biofilm formation, serve in the transfer of DNA, motility and in the bacterial attachment to various surfaces. Type IV pili in Shewanella oneidensis are also supposed to play an important role in extracellular electron transfer by the attachment to sediments containing electron acceptors and potentially forming conductive nanowires. Results The potential nanowire type IV pilin PilBac1 from S. oneidensis was characterized by a combination of complementary structural methods and the atomic structure was determined at a resolution of 1.67 Å by X-ray crystallography. PilBac1 consists of one long N-terminal α-helix packed against four antiparallel β-strands, thus revealing the core fold of type IV pilins. In the crystal, PilBac1 forms a parallel dimer with a sodium ion bound to one of the monomers. Interestingly, our PilBac1 crystal structure reveals two unusual features compared to other type IVa pilins: an unusual position of the disulfide bridge and a straight α-helical section, which usually exhibits a pronounced kink. This straight helix leads to a distinct packing in a filament model of PilBac1 based on an EM model of a Neisseria pilus. Conclusions In this study we have described the first structure of a pilin from Shewanella oneidensis. The structure possesses features of the common type IV pilin core, but also exhibits significant variations in the α-helical part and the D-region. Electronic supplementary material The online version of this article (doi:10.1186/s12900-015-0031-7) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Manuela Gorgel
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10c, Aarhus C, 8000, Denmark.
| | - Jakob Jensen Ulstrup
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10c, Aarhus C, 8000, Denmark.
| | - Andreas Bøggild
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10c, Aarhus C, 8000, Denmark.
| | - Nykola C Jones
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, building 1525, Aarhus C, 8000, Denmark.
| | - Søren V Hoffmann
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, building 1525, Aarhus C, 8000, Denmark.
| | - Poul Nissen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10c, Aarhus C, 8000, Denmark.
| | - Thomas Boesen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10c, Aarhus C, 8000, Denmark.
| |
Collapse
|
46
|
Berry JL, Pelicic V. Exceptionally widespread nanomachines composed of type IV pilins: the prokaryotic Swiss Army knives. FEMS Microbiol Rev 2014; 39:134-54. [PMID: 25793961 PMCID: PMC4471445 DOI: 10.1093/femsre/fuu001] [Citation(s) in RCA: 178] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Prokaryotes have engineered sophisticated surface nanomachines that have allowed them to colonize Earth and thrive even in extreme environments. Filamentous machineries composed of type IV pilins, which are associated with an amazing array of properties ranging from motility to electric conductance, are arguably the most widespread since distinctive proteins dedicated to their biogenesis are found in most known species of prokaryotes. Several decades of investigations, starting with type IV pili and then a variety of related systems both in bacteria and archaea, have outlined common molecular and structural bases for these nanomachines. Using type IV pili as a paradigm, we will highlight in this review common aspects and key biological differences of this group of filamentous structures. Using type IV pili as a paradigm, we review common genetic, structural and mechanistic features (many) as well as differences (few) of the exceptionally widespread and functionally versatile prokaryotic nano-machines composed of type IV pilins.
Collapse
Affiliation(s)
- Jamie-Lee Berry
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Vladimir Pelicic
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| |
Collapse
|
47
|
Nguyen Y, Sugiman-Marangos S, Harvey H, Bell SD, Charlton CL, Junop MS, Burrows LL. Pseudomonas aeruginosa minor pilins prime type IVa pilus assembly and promote surface display of the PilY1 adhesin. J Biol Chem 2014; 290:601-11. [PMID: 25389296 DOI: 10.1074/jbc.m114.616904] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Type IV pili (T4P) contain hundreds of major subunits, but minor subunits are also required for assembly and function. Here we show that Pseudomonas aeruginosa minor pilins prime pilus assembly and traffic the pilus-associated adhesin and anti-retraction protein, PilY1, to the cell surface. PilV, PilW, and PilX require PilY1 for inclusion in surface pili and vice versa, suggestive of complex formation. PilE requires PilVWXY1 for inclusion, suggesting that it binds a novel interface created by two or more components. FimU is incorporated independently of the others and is proposed to couple the putative minor pilin-PilY1 complex to the major subunit. The production of small amounts of T4P by a mutant lacking the minor pilin operon was traced to expression of minor pseudopilins from the P. aeruginosa type II secretion (T2S) system, showing that under retraction-deficient conditions, T2S minor subunits can prime T4P assembly. Deletion of all minor subunits abrogated pilus assembly. In a strain lacking the minor pseudopilins, PilVWXY1 and either FimU or PilE comprised the minimal set of components required for pilus assembly. Supporting functional conservation of T2S and T4P minor components, our 1.4 Å crystal structure of FimU revealed striking architectural similarity to its T2S ortholog GspH, despite minimal sequence identity. We propose that PilVWXY1 form a priming complex for assembly and that PilE and FimU together stably couple the complex to the major subunit. Trafficking of the anti-retraction factor PilY1 to the cell surface allows for production of pili of sufficient length to support adherence and motility.
Collapse
Affiliation(s)
- Ylan Nguyen
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
| | - Seiji Sugiman-Marangos
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
| | - Hanjeong Harvey
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
| | - Stephanie D Bell
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
| | - Carmen L Charlton
- the Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta T6G 2R3, Canada, the Provincial Laboratory for Public Health, Edmonton, Alberta T6G 2J2, Canada, and
| | - Murray S Junop
- the Department of Biochemistry, Western University, London, Ontario N6A 3K7, Canada
| | - Lori L Burrows
- From the Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3Z5, Canada,
| |
Collapse
|
48
|
Invasive meningococcal disease: a disease of the endothelial cells. Trends Mol Med 2014; 20:571-8. [PMID: 25178566 DOI: 10.1016/j.molmed.2014.08.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/06/2014] [Accepted: 08/07/2014] [Indexed: 02/04/2023]
Abstract
Neisseria meningitidis is an extracellular pathogen, which, once in the bloodstream, has the ability to form microcolonies on the apical surface of endothelia. Pathogen interaction with microvessels is mediated by bacterial type IV pili and two receptors on endothelial cells: CD147 and the β2-adrenoceptor. CD147 facilitates the adhesion of diplococci to the endothelium, whereas the β2-adrenoceptor facilitates cell signaling, and crossing of the blood-brain barrier. In this review, we discuss how meningococcal interaction with endothelial cells is responsible for the specific clinical features of invasive meningococcal infection such as meningitis, and a peripheral thrombotic/vascular leakage syndrome possibly leading to purpura fulminans.
Collapse
|
49
|
Siri MI, Sanabria A, Boucher C, Pianzzola MJ. New type IV pili-related genes involved in early stages of Ralstonia solanacearum potato infection. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:712-24. [PMID: 24625029 DOI: 10.1094/mpmi-07-13-0210-r] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
This study provides insights into the pathogenesis of Ralstonia solanacearum, in particular with regards to strains belonging to phylotype IIB, sequevar 1 (IIB-1) and their interaction with potato, its natural host. We performed a comparative genomic analysis among IIB-1 R. solanacearum strains with different levels of virulence in order to identify candidate virulence genes. With this approach, we identified a 33.7-kb deletion in a strain showing reduced virulence on potato. This region contains a cluster of six genes putatively involved in type IV pili (Tfp) biogenesis. Functional analysis suggests that these proteins contribute to several Tfp-related functions such as twitching motility and biofilm formation. In addition, this genetic cluster was found to contribute to early bacterial wilt pathogenesis and colonization fitness of potato roots.
Collapse
|
50
|
Affiliation(s)
| | - Jeremy P Derrick
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| |
Collapse
|