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Van Eyssen SR, Samarkina A, Isbilen O, Zeden MS, Volkan E. FimH and Type 1 Pili Mediated Tumor Cell Cytotoxicity by Uropathogenic Escherichia coli In Vitro. Pathogens 2023; 12:751. [PMID: 37375441 DOI: 10.3390/pathogens12060751] [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: 04/11/2023] [Revised: 05/20/2023] [Accepted: 05/21/2023] [Indexed: 06/29/2023] Open
Abstract
Uropathogenic Escherichia coli express hairlike proteinaceous surface projections, known as chaperone-usher pathway (CUP) pili. Type 1 pili are CUP pili with well-established pathogenic properties. The FimH adhesin subunit of type 1 pili plays a key role in the pathogenesis of urinary tract infections (UTIs) as it mediates the adhesion of the bacteria to urothelial cells of the bladder. In this study, two breast cancer cell lines, MDA-MB-231 and MCF-7, were used to demonstrate the cytotoxic activities of type 1 piliated uropathogenic E. coli UTI89 on breast cancer cells in a type 1 pili and FimH-mediated manner. E. coli were grown in static and shaking conditions to induce or inhibit optimal type 1 pili biogenesis, respectively. Deletion constructs of UTI89 ΔfimH and a complemented strain (UTI89 ΔfimH/pfimH) were further utilized to genetically assess the effect of type 1 pili and FimH on cancer cell viability. After incubation with the different strains, cytotoxicity was measured using trypan blue exclusion assays. UTI89 grown statically caused significant cytotoxicity in both breast cancer cell lines whereas cytotoxicity was reduced when the cells were incubated with bacteria grown under shaking conditions. The incubation of both MDA-MB-231 and MCF-7 with UTI89 Δfim operon or ΔfimH showed a significant reduction in cytotoxicity exerted by the bacterial strains, revealing that type 1 pili expression was necessary for cytotoxicity. Complementing the ΔfimH strain with pfimH reversed the phenotype, leading to a significant increase in cytotoxicity. Incubating type 1 pili expressing bacteria with the competitive FimH inhibitor D-mannose before cancer cell treatment also led to a significant reduction in cytotoxicity on both MDA-MB-231 and MCF-7 cancer cells, compared to vehicle control or D-mannose alone, indicating the requirement for functional FimH for cytotoxicity. Overall, our results reveal that, as opposed to UTI89 lacking type 1 pili, type 1 piliated UTI89 causes significant cancer cell mortality in a FimH-mediated manner, that is decreased with D-mannose.
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Affiliation(s)
- Shelly Roselyn Van Eyssen
- Biotechnology Research Center, Cyprus International University, Northern Cyprus, Mersin 10, 99258 Nicosia, Turkey
| | - Anastasia Samarkina
- Biotechnology Research Center, Cyprus International University, Northern Cyprus, Mersin 10, 99258 Nicosia, Turkey
| | - Ovgu Isbilen
- Biotechnology Research Center, Cyprus International University, Northern Cyprus, Mersin 10, 99258 Nicosia, Turkey
- Department of Pharmacy, Faculty of Pharmacy, Cyprus International University, Northern Cyprus, Mersin 10, 99258 Nicosia, Turkey
| | - Merve Suzan Zeden
- Biotechnology Research Center, Cyprus International University, Northern Cyprus, Mersin 10, 99258 Nicosia, Turkey
- Department of Microbiology, School of Biological and Chemical Sciences, University of Galway, H91TK33 Galway, Ireland
| | - Ender Volkan
- Biotechnology Research Center, Cyprus International University, Northern Cyprus, Mersin 10, 99258 Nicosia, Turkey
- Department of Pharmacy, Faculty of Pharmacy, Cyprus International University, Northern Cyprus, Mersin 10, 99258 Nicosia, Turkey
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2
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He LH, Wang H, Liu Y, Kang M, Li T, Li CC, Tong AP, Zhu YB, Song YJ, Savarino SJ, Prouty MG, Xia D, Bao R. Chaperone-tip adhesin complex is vital for synergistic activation of CFA/I fimbriae biogenesis. PLoS Pathog 2020; 16:e1008848. [PMID: 33007034 PMCID: PMC7531860 DOI: 10.1371/journal.ppat.1008848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 07/30/2020] [Indexed: 02/05/2023] Open
Abstract
Colonization factor CFA/I defines the major adhesive fimbriae of enterotoxigenic Escherichia coli and mediates bacterial attachment to host intestinal epithelial cells. The CFA/I fimbria consists of a tip-localized minor adhesive subunit, CfaE, and thousands of copies of the major subunit CfaB polymerized into an ordered helical rod. Biosynthesis of CFA/I fimbriae requires the assistance of the periplasmic chaperone CfaA and outer membrane usher CfaC. Although the CfaE subunit is proposed to initiate the assembly of CFA/I fimbriae, how it performs this function remains elusive. Here, we report the establishment of an in vitro assay for CFA/I fimbria assembly and show that stabilized CfaA-CfaB and CfaA-CfaE binary complexes together with CfaC are sufficient to drive fimbria formation. The presence of both CfaA-CfaE and CfaC accelerates fimbria formation, while the absence of either component leads to linearized CfaB polymers in vitro. We further report the crystal structure of the stabilized CfaA-CfaE complex, revealing features unique for biogenesis of Class 5 fimbriae.
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Affiliation(s)
- Li-hui He
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Hao Wang
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States of America
- Enteric Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, United States of America
| | - Yang Liu
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States of America
- Enteric Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, United States of America
| | - Mei Kang
- Department of Laboratory medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Tao Li
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Chang-cheng Li
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Ai-ping Tong
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yi-bo Zhu
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Ying-jie Song
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Stephen J. Savarino
- Enteric Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, United States of America
- Department of Pediatrics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States of America
| | - Michael G. Prouty
- Enteric Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD, United States of America
| | - Di Xia
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Rui Bao
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
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3
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Pandey NK, Verma G, Kushwaha GS, Suar M, Bhavesh NS. Crystal structure of the usher chaperone YadV reveals a monomer with the proline lock in closed conformation suggestive of an intermediate state. FEBS Lett 2020; 594:3057-3066. [DOI: 10.1002/1873-3468.13883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/15/2020] [Accepted: 07/02/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Nishant Kumar Pandey
- Transcription Regulation Group International Centre for Genetic Engineering and Biotechnology (ICGEB) New Delhi India
- School of Biotechnology Kalinga Institute of Industrial Technology (KIIT), (Deemed to be University) Bhubaneswar India
| | - Garima Verma
- Transcription Regulation Group International Centre for Genetic Engineering and Biotechnology (ICGEB) New Delhi India
| | - Gajraj Singh Kushwaha
- Transcription Regulation Group International Centre for Genetic Engineering and Biotechnology (ICGEB) New Delhi India
| | - Mrutyunjay Suar
- School of Biotechnology Kalinga Institute of Industrial Technology (KIIT), (Deemed to be University) Bhubaneswar India
| | - Neel Sarovar Bhavesh
- Transcription Regulation Group International Centre for Genetic Engineering and Biotechnology (ICGEB) New Delhi India
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4
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Zhang Z, Bai M, Barbosa GO, Chen A, Wei Y, Luo S, Wang X, Wang B, Tsukui T, Li H, Sheppard D, Kornberg TB, Ma DK. Broadly conserved roles of TMEM131 family proteins in intracellular collagen assembly and secretory cargo trafficking. SCIENCE ADVANCES 2020; 6:eaay7667. [PMID: 32095531 PMCID: PMC7015688 DOI: 10.1126/sciadv.aay7667] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 11/26/2019] [Indexed: 06/10/2023]
Abstract
Collagen is the most abundant protein in animals. Its dysregulation contributes to aging and many human disorders, including pathological tissue fibrosis in major organs. How premature collagen proteins in the endoplasmic reticulum (ER) assemble and route for secretion remains molecularly undefined. From an RNA interference screen, we identified an uncharacterized Caenorhabditis elegans gene tmem-131, deficiency of which impairs collagen production and activates ER stress response. We find that amino termini of human TMEM131 contain bacterial PapD chaperone-like domains, which recruit premature collagen monomers for proper assembly and secretion. Carboxy termini of TMEM131 interact with TRAPPC8, a component of the TRAPP tethering complex, to drive collagen cargo trafficking from ER to the Golgi. We provide evidence that previously undescribed roles of TMEM131 in collagen recruitment and secretion are evolutionarily conserved in C. elegans, Drosophila, and humans.
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Affiliation(s)
- Zhe Zhang
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Meirong Bai
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Guilherme Oliveira Barbosa
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Andrew Chen
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Yuehua Wei
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Shuo Luo
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Xin Wang
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Bingying Wang
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Tatsuya Tsukui
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Hao Li
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Dean Sheppard
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Thomas B. Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Dengke K. Ma
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA
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5
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Inhibition of protein interactions: co-crystalized protein-protein interfaces are nearly as good as holo proteins in rigid-body ligand docking. J Comput Aided Mol Des 2018; 32:769-779. [PMID: 30003468 DOI: 10.1007/s10822-018-0124-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 05/22/2018] [Indexed: 12/15/2022]
Abstract
Modulating protein interaction pathways may lead to the cure of many diseases. Known protein-protein inhibitors bind to large pockets on the protein-protein interface. Such large pockets are detected also in the protein-protein complexes without known inhibitors, making such complexes potentially druggable. The inhibitor-binding site is primary defined by the side chains that form the largest pocket in the protein-bound conformation. Low-resolution ligand docking shows that the success rate for the protein-bound conformation is close to the one for the ligand-bound conformation, and significantly higher than for the apo conformation. The conformational change on the protein interface upon binding to the other protein results in a pocket employed by the ligand when it binds to that interface. This proof-of-concept study suggests that rather than using computational pocket-opening procedures, one can opt for an experimentally determined structure of the target co-crystallized protein-protein complex as a starting point for drug design.
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6
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Werneburg GT, Thanassi DG. Pili Assembled by the Chaperone/Usher Pathway in Escherichia coli and Salmonella. EcoSal Plus 2018; 8:10.1128/ecosalplus.ESP-0007-2017. [PMID: 29536829 PMCID: PMC5940347 DOI: 10.1128/ecosalplus.esp-0007-2017] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Indexed: 12/12/2022]
Abstract
Gram-negative bacteria assemble a variety of surface structures, including the hair-like organelles known as pili or fimbriae. Pili typically function in adhesion and mediate interactions with various surfaces, with other bacteria, and with other types of cells such as host cells. The chaperone/usher (CU) pathway assembles a widespread class of adhesive and virulence-associated pili. Pilus biogenesis by the CU pathway requires a dedicated periplasmic chaperone and integral outer membrane protein termed the usher, which forms a multifunctional assembly and secretion platform. This review addresses the molecular and biochemical aspects of the CU pathway in detail, focusing on the type 1 and P pili expressed by uropathogenic Escherichia coli as model systems. We provide an overview of representative CU pili expressed by E. coli and Salmonella, and conclude with a discussion of potential approaches to develop antivirulence therapeutics that interfere with pilus assembly or function.
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Affiliation(s)
- Glenn T. Werneburg
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, USA
- Center for Infectious Diseases, Stony Brook University, Stony Brook, NY, USA
| | - David G. Thanassi
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, USA
- Center for Infectious Diseases, Stony Brook University, Stony Brook, NY, USA
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7
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Zeng L, Zhang L, Wang P, Meng G. Structural basis of host recognition and biofilm formation by Salmonella Saf pili. eLife 2017; 6:28619. [PMID: 29125121 PMCID: PMC5700814 DOI: 10.7554/elife.28619] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 11/08/2017] [Indexed: 12/21/2022] Open
Abstract
Pili are critical in host recognition, colonization and biofilm formation during bacterial infection. Here, we report the crystal structures of SafD-dsc and SafD-SafA-SafA (SafDAA-dsc) in Saf pili. Cell adherence assays show that SafD and SafA are both required for host recognition, suggesting a poly-adhesive mechanism for Saf pili. Moreover, the SafDAA-dsc structure, as well as SAXS characterization, reveals an unexpected inter-molecular oligomerization, prompting the investigation of Saf-driven self-association in biofilm formation. The bead/cell aggregation and biofilm formation assays are used to demonstrate the novel function of Saf pili. Structure-based mutants targeting the inter-molecular hydrogen bonds and complementary architecture/surfaces in SafDAA-dsc dimers significantly impaired the Saf self-association activity and biofilm formation. In summary, our results identify two novel functions of Saf pili: the poly-adhesive and self-associating activities. More importantly, Saf-Saf structures and functional characterizations help to define a pili-mediated inter-cellular oligomerizaiton mechanism for bacterial aggregation, colonization and ultimate biofilm formation.
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Affiliation(s)
- Longhui Zeng
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui-Jin Hospital, Shanghai JiaoTong University School of Medicine and School of Life Sciences and Biotechnology, Shanghai JiaoTong University, Shanghai, China
| | - Li Zhang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui-Jin Hospital, Shanghai JiaoTong University School of Medicine and School of Life Sciences and Biotechnology, Shanghai JiaoTong University, Shanghai, China
| | - Pengran Wang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui-Jin Hospital, Shanghai JiaoTong University School of Medicine and School of Life Sciences and Biotechnology, Shanghai JiaoTong University, Shanghai, China
| | - Guoyu Meng
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui-Jin Hospital, Shanghai JiaoTong University School of Medicine and School of Life Sciences and Biotechnology, Shanghai JiaoTong University, Shanghai, China
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8
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Larsonneur F, Martin FA, Mallet A, Martinez-Gil M, Semetey V, Ghigo JM, Beloin C. Functional analysis of Escherichia coli Yad fimbriae reveals their potential role in environmental persistence. Environ Microbiol 2016; 18:5228-5248. [PMID: 27696649 DOI: 10.1111/1462-2920.13559] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Initial adhesion of bacterial cells to surfaces or host tissues is a key step in colonisation and biofilm formation processes, and is mediated by cell surface appendages. It was previously demonstrated that Escherichia coli K-12 possesses an arsenal of silenced chaperone-usher fimbriae that were functional when constitutively expressed. Among them, production of prevalent Yad fimbriae induces adhesion to abiotic surfaces. Functional characterisation of Yad fimbriae were undertook, and YadN was identified as the most abundant and potential major pilin, and YadC as the potential tip-protein of Yad fimbriae. It was showed that Yad production participates to binding of E. coli K-12 to human eukaryotic cells (Caco-2) and inhibits macrophage phagocytosis, but also enhances E. coli K-12 binding to xylose, a major component of the plant cell wall, through its tip-lectin YadC. Consistently, it was demonstrated that Yad production provides E. coli with a competitive advantage in colonising corn seed rhizospheres. The latter phenotype is correlated with induction of Yad expression at temperatures below 37°C, and under anaerobic conditions, through a complex regulatory network. Taken together, these results suggest that Yad fimbriae are versatile adhesins that beyond potential capacities to modulate host-pathogen interactions might contribute to E. coli environmental persistence.
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Affiliation(s)
- Fanny Larsonneur
- Institut Pasteur, Unité de Génétique des Biofilms, 28 rue du Dr. Roux 75724, Paris cedex, France.,Ecole Doctorale Bio Sorbonne Paris Cité (BioSPC), Université Paris Diderot, Cellule Pasteur, rue du Dr. Roux 75724, Paris cedex, France
| | - Fernando A Martin
- Institut Pasteur, Unité de Génétique des Biofilms, 28 rue du Dr. Roux 75724, Paris cedex, France
| | - Adeline Mallet
- Institut Pasteur, Ultrapole, 28 rue du Dr. Roux 75724, Paris cedex, France
| | - Marta Martinez-Gil
- Institut Pasteur, Unité de Génétique des Biofilms, 28 rue du Dr. Roux 75724, Paris cedex, France
| | - Vincent Semetey
- PSL Research University, Chimie ParisTech - CNRS, Institut de Recherche de Chimie Paris, Paris, 75005, France
| | - Jean-Marc Ghigo
- Institut Pasteur, Unité de Génétique des Biofilms, 28 rue du Dr. Roux 75724, Paris cedex, France
| | - Christophe Beloin
- Institut Pasteur, Unité de Génétique des Biofilms, 28 rue du Dr. Roux 75724, Paris cedex, France
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9
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Holmes DE, Dang Y, Walker DJF, Lovley DR. The electrically conductive pili of Geobacter species are a recently evolved feature for extracellular electron transfer. Microb Genom 2016; 2:e000072. [PMID: 28348867 DOI: 10.1099/mgen.0.000072] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 05/31/2016] [Indexed: 12/14/2022] Open
Abstract
The electrically conductive pili (e-pili) of Geobactersulfurreducens have environmental and practical significance because they can facilitate electron transfer to insoluble Fe(III) oxides; to other microbial species; and through electrically conductive biofilms. E-pili conductivity has been attributed to the truncated PilA monomer, which permits tight packing of aromatic amino acids to form a conductive path along the length of e-pili. In order to better understand the evolution and distribution of e-pili in the microbial world, type IVa PilA proteins from various Gram-negative and Gram-positive bacteria were examined with a particular emphasis on Fe(III)-respiring bacteria. E-pilin genes are primarily restricted to a tight phylogenetic group in the order Desulfuromonadales. The downstream gene in all but one of the Desulfuromonadales that possess an e-pilin gene is a gene previously annotated as 'pilA-C' that has characteristics suggesting that it may encode an outer-membrane protein. Other genes associated with pilin function are clustered with e-pilin and 'pilA-C' genes in the Desulfuromonadales. In contrast, in the few bacteria outside the Desulfuromonadales that contain e-pilin genes, the other genes required for pilin function may have been acquired through horizontal gene transfer. Of the 95 known Fe(III)-reducing micro-organisms for which genomes are available, 80 % lack e-pilin genes, suggesting that e-pili are just one of several mechanisms involved in extracellular electron transport. These studies provide insight into where and when e-pili are likely to contribute to extracellular electron transport processes that are biogeochemically important and involved in bioenergy conversions.
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Affiliation(s)
- Dawn E Holmes
- 1Department of Microbiology, University of Massachusetts Amherst, Amherst, MA, USA.,2Department of Physical and Biological Sciences, Western New England University, Springfield, MA, USA
| | - Yan Dang
- 1Department of Microbiology, University of Massachusetts Amherst, Amherst, MA, USA
| | - David J F Walker
- 1Department of Microbiology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Derek R Lovley
- 1Department of Microbiology, University of Massachusetts Amherst, Amherst, MA, USA
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The Escherichia coli P and Type 1 Pilus Assembly Chaperones PapD and FimC Are Monomeric in Solution. J Bacteriol 2016; 198:2360-9. [PMID: 27353649 PMCID: PMC4984555 DOI: 10.1128/jb.00366-16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 06/19/2016] [Indexed: 01/07/2023] Open
Abstract
UNLABELLED The chaperone/usher pathway is used by Gram-negative bacteria to assemble adhesive surface structures known as pili or fimbriae. Uropathogenic strains of Escherichia coli use this pathway to assemble P and type 1 pili, which facilitate colonization of the kidney and bladder, respectively. Pilus assembly requires a periplasmic chaperone and outer membrane protein termed the usher. The chaperone allows folding of pilus subunits and escorts the subunits to the usher for polymerization into pili and secretion to the cell surface. Based on previous structures of mutant versions of the P pilus chaperone PapD, it was suggested that the chaperone dimerizes in the periplasm as a self-capping mechanism. Such dimerization is counterintuitive because the chaperone G1 strand, important for chaperone-subunit interaction, is buried at the dimer interface. Here, we show that the wild-type PapD chaperone also forms a dimer in the crystal lattice; however, the dimer interface is different from the previously solved structures. In contrast to the crystal structures, we found that both PapD and the type 1 pilus chaperone, FimC, are monomeric in solution. Our findings indicate that pilus chaperones do not sequester their G1 β-strand by forming a dimer. Instead, the chaperones may expose their G1 strand for facile interaction with pilus subunits. We also found that the type 1 pilus adhesin, FimH, is flexible in solution while in complex with its chaperone, whereas the P pilus adhesin, PapGII, is rigid. Our study clarifies a crucial step in pilus biogenesis and reveals pilus-specific differences that may relate to biological function. IMPORTANCE Pili are critical virulence factors for many bacterial pathogens. Uropathogenic E. coli relies on P and type 1 pili assembled by the chaperone/usher pathway to adhere to the urinary tract and establish infection. Studying pilus assembly is important for understanding mechanisms of protein secretion, as well as for identifying points for therapeutic intervention. Pilus biogenesis is a multistep process. This work investigates the oligomeric state of the pilus chaperone in the periplasm, which is important for understanding early assembly events. Our work unambiguously demonstrates that both PapD and FimC chaperones are monomeric in solution. We further demonstrate that the solution behavior of the FimH and PapGII adhesins differ, which may be related to functional differences between the two pilus systems.
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11
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Busch A, Phan G, Waksman G. Molecular mechanism of bacterial type 1 and P pili assembly. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2015; 373:rsta.2013.0153. [PMID: 25624519 DOI: 10.1098/rsta.2013.0153] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The formation of adhesive surface structures called pili or fimbriae ('bacterial hair') is an important contributor towards bacterial pathogenicity and persistence. To fight often chronic or recurrent bacterial infections such as urinary tract infections, it is necessary to understand the molecular mechanism of the nanomachines assembling such pili. Here, we focus on the so far best-known pilus assembly machinery: the chaperone-usher pathway producing the type 1 and P pili, and highlight the most recently acquired structural knowledge. First, we describe the subunits' structure and the molecular role of the periplasmic chaperone. Second, we focus on the outer-membrane usher structure and the catalytic mechanism of usher-mediated pilus biogenesis. Finally, we describe how the detailed understanding of the chaperone-usher pathway at a molecular level has paved the way for the design of a new generation of bacterial inhibitors called 'pilicides'.
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Affiliation(s)
- Andreas Busch
- Institute of Structural and Molecular Biology, University College London and Birkbeck College, Malet Street, London WC1E 7HX, UK
| | - Gilles Phan
- Institute of Structural and Molecular Biology, University College London and Birkbeck College, Malet Street, London WC1E 7HX, UK
| | - Gabriel Waksman
- Institute of Structural and Molecular Biology, University College London and Birkbeck College, Malet Street, London WC1E 7HX, UK
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12
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Bao R, Fordyce A, Chen YX, McVeigh A, Savarino SJ, Xia D. Structure of CfaA suggests a new family of chaperones essential for assembly of class 5 fimbriae. PLoS Pathog 2014; 10:e1004316. [PMID: 25122114 PMCID: PMC4133393 DOI: 10.1371/journal.ppat.1004316] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 06/27/2014] [Indexed: 01/22/2023] Open
Abstract
Adhesive pili on the surface of pathogenic bacteria comprise polymerized pilin subunits and are essential for initiation of infections. Pili assembled by the chaperone-usher pathway (CUP) require periplasmic chaperones that assist subunit folding, maintain their stability, and escort them to the site of bioassembly. Until now, CUP chaperones have been classified into two families, FGS and FGL, based on the short and long length of the subunit-interacting loops between its F1 and G1 β-strands, respectively. CfaA is the chaperone for assembly of colonization factor antigen I (CFA/I) pili of enterotoxigenic E. coli (ETEC), a cause of diarrhea in travelers and young children. Here, the crystal structure of CfaA along with sequence analyses reveals some unique structural and functional features, leading us to propose a separate family for CfaA and closely related chaperones. Phenotypic changes resulting from mutations in regions unique to this chaperone family provide insight into their function, consistent with involvement of these regions in interactions with cognate subunits and usher proteins during pilus assembly.
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Affiliation(s)
- Rui Bao
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - April Fordyce
- Enteric Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Yu-Xing Chen
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| | - Annette McVeigh
- Enteric Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Stephen J Savarino
- Enteric Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, Maryland, United States of America; Department of Pediatrics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Di Xia
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
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Geibel S, Waksman G. The molecular dissection of the chaperone–usher pathway. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:1559-67. [DOI: 10.1016/j.bbamcr.2013.09.023] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 09/25/2013] [Accepted: 09/30/2013] [Indexed: 01/11/2023]
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Ordered and ushered; the assembly and translocation of the adhesive type I and p pili. BIOLOGY 2013; 2:841-60. [PMID: 24833049 PMCID: PMC3960871 DOI: 10.3390/biology2030841] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 05/21/2013] [Accepted: 05/24/2013] [Indexed: 11/17/2022]
Abstract
Type I and P pili are chaperone-usher pili of uropathogenic Escherichia coli, which allow bacteria to adhere to host cell receptors. Pilus formation and secretion are orchestrated by two accessory proteins, a chaperone, which catalyses pilus subunit folding and maintains them in a polymerization-competent state, and an outer membrane-spanning nanomachine, the usher, which choreographs their assembly into a pilus and drives their secretion through the membrane. In this review, recent structures and kinetic studies are combined to examine the mechanism of type I and P pili assembly, as it is currently known. We also investigate how the knowledge of pilus biogenesis mechanisms has been exploited to design selective inhibitors of the process.
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Enterotoxigenic Escherichia coli CS1 pilus: not one structure but several. J Bacteriol 2013; 195:1357-9. [PMID: 23354749 DOI: 10.1128/jb.00053-13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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