Scholars@Duke
Margarethe Joanna Kuehn

Margarethe Joanna Kuehn

Associate Professor of Biochemistry
Biochemistry
kuehn@duke.edu
Duke Box 3711, Durham, NC 27710
Research Drive, 220A Nanaline H Duke, Durham, NC 27710

Selected Publications

Extracellular Vesicles and Bacteriophages: New Directions in Environmental Biocolloid Research.

Journal Article Environ Sci Technol · November 7, 2023 There is a long-standing appreciation among environmental engineers and scientists regarding the importance of biologically derived colloidal particles and their environmental fate. This interest has been recently renewed in considering bacteriophages and ... Full text Link to item Cite

Characterizing the Transport and Surface Affinity of Extracellular Vesicles Isolated from Yeast and Bacteria in Well-Characterized Porous Media.

Journal Article Environ Sci Technol · September 5, 2023 Extracellular vesicles (EVs) are membrane-bounded, nanosized particles, produced and secreted by all biological cell types. EVs are ubiquitous in the environment, operating in various roles including intercellular communication and plant immune modulation. ... Full text Link to item Cite

Comparative electrokinetic properties of extracellular vesicles produced by yeast and bacteria.

Journal Article Colloids Surf B Biointerfaces · May 2023 Extracellular vesicles (EVs) are nano-sized, biocolloidal proteoliposomes that have been shown to be produced by all cell types studied to date and are ubiquitous in the environment. Extensive literature on colloidal particles has demonstrated the implicat ... Full text Link to item Cite

Proteomic Profiling Reveals Distinct Bacterial Extracellular Vesicle Subpopulations with Possibly Unique Functionality.

Journal Article Appl Environ Microbiol · January 31, 2023 Bacterial outer membrane vesicles (OMVs) are 20- to 200-nm secreted packages of lipids, small molecules, and proteins that contribute to diverse bacterial processes. In plant systems, OMVs from pathogenic and beneficial strains elicit plant immune response ... Full text Link to item Cite

The extracellular vesicle generation paradox: a bacterial point of view.

Journal Article EMBO J · November 2, 2021 All bacteria produce secreted vesicles that carry out a variety of important biological functions. These extracellular vesicles can improve adaptation and survival by relieving bacterial stress and eliminating toxic compounds, as well as by facilitating me ... Full text Link to item Cite

Microbial vesicle-mediated communication: convergence to understand interactions within and between domains of life.

Journal Article Environ Sci Process Impacts · May 26, 2021 All cells produce extracellular vesicles (EVs). These biological packages contain complex mixtures of molecular cargo and have a variety of functions, including interkingdom communication. Recent discoveries highlight the roles microbial EVs may play in th ... Full text Link to item Cite

Protective plant immune responses are elicited by bacterial outer membrane vesicles.

Journal Article Cell Rep · January 19, 2021 Bacterial outer membrane vesicles (OMVs) perform a variety of functions in bacterial survival and virulence. In mammalian systems, OMVs activate immune responses and are exploited as vaccines. However, little work has focused on the interactions of OMVs wi ... Full text Open Access Link to item Cite

Differential Packaging Into Outer Membrane Vesicles Upon Oxidative Stress Reveals a General Mechanism for Cargo Selectivity.

Journal Article Front Microbiol · 2021 Selective cargo packaging into bacterial extracellular vesicles has been reported and implicated in many biological processes, however, the mechanism behind the selectivity has remained largely unexplored. In this study, proteomic analysis of outer membran ... Full text Link to item Cite

Dynamin-related Irgm proteins modulate LPS-induced caspase-11 activation and septic shock.

Journal Article EMBO Rep · November 5, 2020 Inflammation associated with gram-negative bacterial infections is often instigated by the bacterial cell wall component lipopolysaccharide (LPS). LPS-induced inflammation and resulting life-threatening sepsis are mediated by the two distinct LPS receptors ... Full text Link to item Cite

Staphylococcus aureus secretes immunomodulatory RNA and DNA via membrane vesicles.

Journal Article Sci Rep · October 26, 2020 Bacterial-derived RNA and DNA can function as ligands for intracellular receptor activation and induce downstream signaling to modulate the host response to bacterial infection. The mechanisms underlying the secretion of immunomodulatory RNA and DNA by pat ... Full text Link to item Cite

Outer Membrane Vesiculation Facilitates Surface Exchange and In Vivo Adaptation of Vibrio cholerae.

Journal Article Cell Host Microbe · February 12, 2020 Gram-negative bacteria release outer membrane vesicles into the external milieu to deliver effector molecules that alter the host and facilitate virulence. Vesicle formation is driven by phospholipid accumulation in the outer membrane and regulated by the  ... Full text Open Access Link to item Cite

Dynamin-related Irgm proteins modulate LPS-induced caspase-4 activation and septic shock

Journal Article · 2020 ABSTRACT Inflammation associated with gram-negative bacterial infections is often instigated by the bacterial cell wall component lipopolysaccharide (LPS). LPS-induced inflammation and resulting life-threatening sepsis are mediated by the two dist ... Full text Open Access Cite

Pseudomonas aeruginosa Leucine Aminopeptidase Influences Early Biofilm Composition and Structure via Vesicle-Associated Antibiofilm Activity.

Journal Article mBio · November 19, 2019 Pseudomonas aeruginosa, known as one of the leading causes of disease in cystic fibrosis (CF) patients, secretes a variety of proteases. These enzymes contribute significantly to P. aeruginosa pathogenesis and biofilm formation in the chronic colonization ... Full text Link to item Cite

Bacterial vesicles: Double agents for plant defense

Conference MOLECULAR PLANT-MICROBE INTERACTIONS · October 1, 2019 Link to item Cite

Inflammasome Activation by Bacterial Outer Membrane Vesicles Requires Guanylate Binding Proteins.

Journal Article mBio · October 3, 2017 The Gram-negative bacterial cell wall component lipopolysaccharide (LPS) is recognized by the noncanonical inflammasome protein caspase-11 in the cytosol of infected host cells and thereby prompts an inflammatory immune response linked to sepsis. Host guan ... Full text Open Access Link to item Cite

Breaking the bilayer: OMV formation during environmental transitions.

Journal Article Microb Cell · February 3, 2017 Gram-negative bacteria maintain the barrier properties of the outer membrane (OM) in a wide array of physiological conditions despite their inability to degrade lipopolysaccharide (LPS) and protein material present in the outer leaflet of the OM. Through c ... Full text Open Access Link to item Cite

Environmentally controlled bacterial vesicle-mediated export.

Journal Article Cell Microbiol · November 2016 Over the past two decades, researchers studying both microbial and host cell communities have gained an appreciation for the ability of bacteria to produce, regulate, and functionally utilize outer membrane vesicles (OMVs) as a means to survive and interac ... Full text Open Access Link to item Cite

Outer Membrane Vesicle Production Facilitates LPS Remodeling and Outer Membrane Maintenance in Salmonella during Environmental Transitions.

Journal Article mBio · October 18, 2016 UNLABELLED: The ability of Gram-negative bacteria to carefully modulate outer membrane (OM) composition is essential to their survival. However, the asymmetric and heterogeneous structure of the Gram-negative OM poses unique challenges to the cell's succes ... Full text Open Access Link to item Cite

A standardized method to determine the concentration of extracellular vesicles using tunable resistive pulse sensing.

Journal Article J Extracell Vesicles · 2016 BACKGROUND: Understanding the pathogenic role of extracellular vesicles (EVs) in disease and their potential diagnostic and therapeutic utility is extremely reliant on in-depth quantification, measurement and identification of EV sub-populations. Quantific ... Full text Open Access Link to item Cite

Outer-membrane vesicles from Gram-negative bacteria: biogenesis and functions.

Journal Article Nat Rev Microbiol · October 2015 Outer-membrane vesicles (OMVs) are spherical buds of the outer membrane filled with periplasmic content and are commonly produced by Gram-negative bacteria. The production of OMVs allows bacteria to interact with their environment, and OMVs have been found ... Full text Link to item Cite

NlpI-mediated modulation of outer membrane vesicle production through peptidoglycan dynamics in Escherichia coli.

Journal Article Microbiologyopen · June 2015 Featured Publication Outer membrane vesicles (OMVs) are ubiquitously secreted from the outer membrane (OM) of Gram-negative bacteria. These heterogeneous structures are composed of OM filled with periplasmic content from the site of budding. By analyzing mutants that have vesi ... Full text Open Access Link to item Cite

Genome-Wide Assessment of Outer Membrane Vesicle Production in Escherichia coli.

Journal Article PLoS One · 2015 The production of outer membrane vesicles by Gram-negative bacteria has been well documented; however, the mechanism behind the biogenesis of these vesicles remains unclear. Here a high-throughput experimental method and systems-scale analysis was conducte ... Full text Open Access Link to item Cite

Modulation of bacterial outer membrane vesicle production by envelope structure and content.

Journal Article BMC Microbiol · December 21, 2014 BACKGROUND: Vesiculation is a ubiquitous secretion process of Gram-negative bacteria, where outer membrane vesicles (OMVs) are small spherical particles on the order of 50 to 250 nm composed of outer membrane (OM) and lumenal periplasmic content. Vesicle f ... Full text Open Access Link to item Cite

Protein selection and export via outer membrane vesicles.

Journal Article Biochim Biophys Acta · August 2014 Outer membrane vesicles (OMVs) are constitutively produced by all Gram-negative bacteria. OMVs form when buds from the outer membrane (OM) of cells encapsulate periplasmic material and pinch off from the OM to form spheroid particles approximately 10 to 30 ... Full text Link to item Cite

Quantitative and qualitative preparations of bacterial outer membrane vesicles

Journal Article Methods in Molecular Biology · December 1, 2013 Gram-negative bacterial outer membrane vesicle production and function have been studied using a variety of quantitative and qualitative methods. These types of analyses can be hampered by the use of impure vesicle preparations. Here we describe a set of t ... Full text Open Access Cite

Synthetic effect between envelope stress and lack of outer membrane vesicle production in Escherichia coli.

Journal Article J Bacteriol · September 2013 Outer membrane vesicles (OMVs) are composed of outer membrane and periplasmic components and are ubiquitously secreted by Gram-negative bacteria. OMVs can disseminate virulence factors for pathogenic bacteria as well as serve as an envelope stress response ... Full text Link to item Cite

Stress-induced outer membrane vesicle production by Pseudomonas aeruginosa.

Journal Article J Bacteriol · July 2013 As an opportunistic Gram-negative pathogen, Pseudomonas aeruginosa must be able to adapt and survive changes and stressors in its environment during the course of infection. To aid survival in the hostile host environment, P. aeruginosa has evolved defense ... Full text Open Access Link to item Cite

Envelope control of outer membrane vesicle production in Gram-negative bacteria.

Journal Article Biochemistry · May 7, 2013 Featured Publication All Gram-negative bacteria studied to date have been shown to produce outer membrane vesicles (OMVs), which are budded, released spheres of outer membrane with periplasmic content. OMVs have been implicated in the delivery of virulence factors in pathogene ... Full text Link to item Cite

Quantitative and qualitative preparations of bacterial outer membrane vesicles.

Journal Article Methods Mol Biol · 2013 Gram-negative bacterial outer membrane vesicle production and function have been studied using a variety of quantitative and qualitative methods. These types of analyses can be hampered by the use of impure vesicle preparations. Here we describe a set of t ... Full text Link to item Cite

Functional advantages conferred by extracellular prokaryotic membrane vesicles.

Journal Article J Mol Microbiol Biotechnol · 2013 The absence of subcellular organelles is a characteristic typically used to distinguish prokaryotic from eukaryotic cells. But recent discoveries do not support this dogma. Over the past 50 years, researchers have begun to appreciate and characterize Gram- ... Full text Link to item Cite

Secreted bacterial vesicles as good samaritans.

Journal Article Cell Host Microbe · October 18, 2012 Bacteriodes fragilis and polysaccharide A capsular antigen (PSA) produced by this commensal bacteria can mediate immune tolerance in the gastrointestinal (GI) tract. When looking for naturally secreted forms of PSA, Shen et al. (2012) suprisingly found tha ... Full text Link to item Cite

The inoculum effect and band-pass bacterial response to periodic antibiotic treatment.

Journal Article Mol Syst Biol · 2012 The inoculum effect (IE) refers to the decreasing efficacy of an antibiotic with increasing bacterial density. It represents a unique strategy of antibiotic tolerance and it can complicate design of effective antibiotic treatment of bacterial infections. T ... Full text Open Access Link to item Cite

Offense and defense: microbial membrane vesicles play both ways.

Journal Article Res Microbiol · 2012 Microbes have evolved over millennia to become adapted and specialized to the environments that they occupy. These environments may include water or soil, extreme environments such as hydrothermal vents, and can even include a host organism. To become adap ... Full text Link to item Cite

Contribution of bacterial outer membrane vesicles to innate bacterial defense.

Journal Article BMC Microbiol · December 1, 2011 Featured Publication BACKGROUND: Outer membrane vesicles (OMVs) are constitutively produced by Gram-negative bacteria throughout growth and have proposed roles in virulence, inflammation, and the response to envelope stress. Here we investigate outer membrane vesiculation as a ... Full text Open Access Link to item Cite

Elicitation of epithelial cell-derived immune effectors by outer membrane vesicles of nontypeable Haemophilus influenzae.

Journal Article Infect Immun · November 2011 Outer membrane vesicles (OMVs) are produced by all Gram-negative microorganisms studied to date. The contributions of OMVs to biological processes are diverse and include mediation of bacterial stress responses, selective packaging and secretion of virulen ... Full text Link to item Cite

Recognition of β-strand motifs by RseB is required for σ(E) activity in Escherichia coli.

Journal Article J Bacteriol · November 2011 Gram-negative bacteria react to misfolded proteins in the envelope through a myriad of different stress response pathways. This cohort of pathways allows the bacteria to specifically respond to different types of damage, and many of these have been discove ... Full text Link to item Cite

Context-dependent activation kinetics elicited by soluble versus outer membrane vesicle-associated heat-labile enterotoxin.

Journal Article Infect Immun · September 2011 Enterotoxigenic Escherichia coli (ETEC) is the leading cause of traveler's diarrhea and children's diarrhea worldwide. Among its virulence factors, ETEC produces heat-labile enterotoxin (LT). Most secreted LT is associated with outer membrane vesicles that ... Full text Link to item Cite

Immunization with Salmonella enterica serovar Typhimurium-derived outer membrane vesicles delivering the pneumococcal protein PspA confers protection against challenge with Streptococcus pneumoniae.

Journal Article Infect Immun · February 2011 Gram-negative bacteria produce outer membrane vesicles (OMVs) that serve a variety of functions related to survival and pathogenicity. Periplasmic and outer membrane proteins are naturally captured during vesicle formation. This property has been exploited ... Full text Link to item Cite

Naturally produced outer membrane vesicles from Pseudomonas aeruginosa elicit a potent innate immune response via combined sensing of both lipopolysaccharide and protein components.

Journal Article Infect Immun · September 2010 Pseudomonas aeruginosa is a prevalent opportunistic human pathogen that, like other Gram-negative pathogens, secretes outer membrane vesicles. Vesicles are complex entities composed of a subset of envelope lipid and protein components that have been observ ... Full text Link to item Cite

Heat-labile enterotoxin: beyond G(m1) binding.

Journal Article Toxins (Basel) · June 2010 Enterotoxigenic Escherichia coli (ETEC) is a significant source of morbidity and mortality worldwide. One major virulence factor released by ETEC is the heat-labile enterotoxin LT, which is structurally and functionally similar to cholera toxin. LT consist ... Full text Open Access Link to item Cite

Specificity of the type II secretion systems of enterotoxigenic Escherichia coli and Vibrio cholerae for heat-labile enterotoxin and cholera toxin.

Journal Article J Bacteriol · April 2010 The Gram-negative type II secretion (T2S) system is a multiprotein complex mediating the release of virulence factors from a number of pathogens. While an understanding of the function of T2S components is emerging, little is known about what identifies su ... Full text Link to item Cite

Virulence and immunomodulatory roles of bacterial outer membrane vesicles.

Journal Article Microbiol Mol Biol Rev · March 2010 Outer membrane (OM) vesicles are ubiquitously produced by Gram-negative bacteria during all stages of bacterial growth. OM vesicles are naturally secreted by both pathogenic and nonpathogenic bacteria. Strong experimental evidence exists to categorize OM v ... Full text Link to item Cite

Biological functions and biogenesis of secreted bacterial outer membrane vesicles.

Journal Article Annu Rev Microbiol · 2010 Featured Publication Gram-negative bacteria produce outer membrane vesicles (OMVs) that contain biologically active proteins and perform diverse biological processes. Unlike other secretion mechanisms, OMVs enable bacteria to secrete insoluble molecules in addition to and in c ... Full text Link to item Cite

Residues of heat-labile enterotoxin involved in bacterial cell surface binding.

Journal Article J Bacteriol · May 2009 Enterotoxigenic Escherichia coli (ETEC) is a leading cause of traveler's diarrhea worldwide. One major virulence factor released by this pathogen is the heat-labile enterotoxin LT, which upsets the balance of electrolytes in the intestine. After export, LT ... Full text Link to item Cite

Pseudomonas aeruginosa vesicles associate with and are internalized by human lung epithelial cells.

Journal Article BMC Microbiol · February 3, 2009 BACKGROUND: Pseudomonas aeruginosa is the major pathogen associated with chronic and ultimately fatal lung infections in patients with cystic fibrosis (CF). To investigate how P. aeruginosa-derived vesicles may contribute to lung disease, we explored their ... Full text Open Access Link to item Cite

Release of outer membrane vesicles by Gram-negative bacteria is a novel envelope stress response.

Journal Article Mol Microbiol · January 2007 Featured Publication Conditions that impair protein folding in the Gram-negative bacterial envelope cause stress. The destabilizing effects of stress in this compartment are recognized and countered by a number of signal transduction mechanisms. Data presented here reveal anot ... Full text Open Access Link to item Cite

Purification of outer membrane vesicles from Pseudomonas aeruginosa and their activation of an IL-8 response.

Journal Article Microbes Infect · August 2006 Considerable lung injury results from the inflammatory response to Pseudomonas aeruginosa infections in patients with cystic fibrosis (CF). The P. aeruginosa laboratory strain PAO1, an environmental isolate, and isolates from CF patients were cultured in v ... Full text Link to item Cite

Outer membrane vesicle production by Escherichia coli is independent of membrane instability.

Journal Article J Bacteriol · August 2006 Featured Publication It has been long noted that gram-negative bacteria produce outer membrane vesicles, and recent data demonstrate that vesicles released by pathogenic strains can transmit virulence factors to host cells. However, the mechanism of vesicle release has remaine ... Full text Link to item Cite

Genetically engineered probiotic competition.

Journal Article Gastroenterology · May 2006 Full text Link to item Cite

Bacterial outer membrane vesicles and the host-pathogen interaction.

Journal Article Genes Dev · November 15, 2005 Extracellular secretion of products is the major mechanism by which Gram-negative pathogens communicate with and intoxicate host cells. Vesicles released from the envelope of growing bacteria serve as secretory vehicles for proteins and lipids of Gram-nega ... Full text Link to item Cite

Outer Membrane Vesicles.

Journal Article EcoSal Plus · November 2005 Outer membrane vesicles (blebs) are produced by Escherichia coli, Salmonella, and all other gram-negative bacteria both in vitro and in vivo. Most of the research in the field has focused on the properties of vesicles derived from pathogenic bacteria and t ... Full text Link to item Cite

Enterotoxigenic Escherichia coli vesicles target toxin delivery into mammalian cells.

Journal Article EMBO J · November 24, 2004 Enterotoxigenic Escherichia coli (ETEC) is a prevalent cause of traveler's diarrhea and infant mortality in third-world countries. Heat-labile enterotoxin (LT) is secreted from ETEC via vesicles composed of outer membrane and periplasm. We investigated the ... Full text Link to item Cite

Lipopolysaccharide 3-deoxy-D-manno-octulosonic acid (Kdo) core determines bacterial association of secreted toxins.

Journal Article J Biol Chem · February 27, 2004 Featured Publication In contrast to cholera toxin (CT), which is secreted solubly by Vibrio cholerae across the outer membrane, heat-labile enterotoxin (LT) is retained on the surface of enterotoxigenic Escherichia coli (ETEC) via an interaction with lipopolysaccharide (LPS). ... Full text Link to item Cite

Incorporation of heterologous outer membrane and periplasmic proteins into Escherichia coli outer membrane vesicles.

Journal Article J Biol Chem · January 16, 2004 Featured Publication Gram-negative bacteria shed outer membrane vesicles composed of outer membrane and periplasmic components. Since vesicles from pathogenic bacteria contain virulence factors and have been shown to interact with eukaryotic cells, it has been proposed that ve ... Full text Link to item Cite

The E. coli BaeSR two-component regulatory system

Journal Article Trends in Microbiology · December 1, 2002 Full text Cite

Bacterial density dictates virulence in cholera

Journal Article Trends in Microbiology · October 1, 2002 Full text Cite

Bacterial surface association of heat-labile enterotoxin through lipopolysaccharide after secretion via the general secretory pathway.

Journal Article J Biol Chem · September 6, 2002 Featured Publication Heat-labile enterotoxin (LT) is an important virulence factor expressed by enterotoxigenic Escherichia coli. The route of LT secretion through the outer membrane and the cellular and extracellular localization of secreted LT were examined. Using a fluoresc ... Full text Link to item Cite

FRET probes toxin activity in situ

Journal Article Trends in Microbiology · August 1, 2002 Full text Cite

Surrogate host succumbs to virulent Pseudomonas

Journal Article Trends in Microbiology · May 1, 2002 Full text Cite

Polarized secretion.

Journal Article Trends Microbiol · March 2002 Full text Link to item Cite

Engineering a biosensor from a bacterial periplasmic protein

Journal Article Trends in Microbiology · November 1, 2001 Full text Cite

Bacterial-host-cell tethers.

Journal Article Trends Microbiol · July 2001 Featured Publication Full text Link to item Cite

Bacterial cave dwellers.

Journal Article Trends Microbiol · October 2000 Featured Publication Full text Link to item Cite

Definitive typing of LPS core structures

Journal Article Trends in Microbiology · May 1, 2000 Full text Cite

Enterotoxigenic Escherichia coli secretes active heat-labile enterotoxin via outer membrane vesicles.

Journal Article J Biol Chem · April 28, 2000 Featured Publication Escherichia coli and other Gram-negative bacteria produce outer membrane vesicles during normal growth. Vesicles may contribute to bacterial pathogenicity by serving as vehicles for toxins to encounter host cells. Enterotoxigenic E. coli (ETEC) vesicles we ... Full text Link to item Cite

Lighting the path to virulence

Journal Article Trends in Microbiology · January 1, 2000 Full text Cite

Foreign travel.

Journal Article Trends Microbiol · March 1999 Full text Link to item Cite

Expressed by stress

Journal Article Trends in Microbiology · January 1, 1999 Full text Cite

A divisive role for lipoproteins

Journal Article Trends in Microbiology · January 1, 1999 Full text Cite

COPII-cargo interactions direct protein sorting into ER-derived transport vesicles.

Journal Article Nature · January 8, 1998 Featured Publication Vesicles coated with coat protein complex II (COPII) selectively transport molecules (cargo) and vesicle fusion proteins from the endoplasmic reticulum (ER) to the Golgi complex. We have investigated the role of coat proteins in cargo selection and recruit ... Full text Link to item Cite

New transporter family

Journal Article Trends in Microbiology · January 1, 1998 Full text Cite

Cargo selection and vesicle budding

Journal Article FASEB Journal · December 1, 1997 The cytosolic yeast proteins Secl3-31p, Sec23/24p, and the small GTP binding protein Sarlp form the membrane coat termed COPII. Purified COPII components and GTP form anterograde transport vesicles directly from the endoplasmic reticulum. Cargo capture by ... Cite

COPII and secretory cargo capture into transport vesicles.

Journal Article Curr Opin Cell Biol · August 1997 Featured Publication Yeast cylosolic coat proteins (COPII) direct the formation of vesicles from the endoplasmic reticulum. The vesicles selectively capture both cargo molecules and the secretory machinery that is necessary for the fusion of the vesicle with the recipient comp ... Full text Link to item Cite

Establishing communication via gram-negative bacterial pili.

Journal Article Trends Microbiol · April 1997 Featured Publication Full text Link to item Cite

Leaping into the outer membrane

Journal Article Trends in Microbiology · January 1, 1997 Full text Cite

Cryptococcus and calcineurin

Journal Article Trends in Microbiology · January 1, 1997 Full text Cite

Amino acid permeases require COPII components and the ER resident membrane protein Shr3p for packaging into transport vesicles in vitro.

Journal Article J Cell Biol · November 1996 Featured Publication In S. cerevisiae lacking SHR3, amino acid permeases specifically accumulate in membranes of the endoplasmic reticulum (ER) and fail to be transported to the plasma membrane. We examined the requirements of transport of the permeases from the ER to the Golg ... Full text Open Access Link to item Cite

Structural basis of pilus subunit recognition by the PapD chaperone.

Journal Article Science · November 19, 1993 Featured Publication The assembly of different types of virulence-associated surface fibers called pili in Gram-negative bacteria requires periplasmic chaperones. PapD is the prototype member of the periplasmic chaperone family, and the structural basis of its interactions wit ... Full text Link to item Cite

A novel secretion apparatus for the assembly of adhesive bacterial pili.

Journal Article Trends Microbiol · May 1993 The biogenesis of most types of bacterial pili requires two specialized proteins: a chaperone that caps the pilus subunits in the periplasm, and an outer membrane usher that receives the subunits and serves as an assembly platform. This secretion and assem ... Full text Link to item Cite

Fimbriation of Pseudomonas cepacia.

Journal Article Infect Immun · May 1992 Fimbriae (pili) on the surface of bacteria have been suggested to facilitate adherence to mucosal epithelial surfaces. Three Pseudomonas cepacia cystic fibrosis isolates were screened for their ability to agglutinate erythrocytes (HA), a characteristic of ... Full text Link to item Cite

Conserved immunoglobulin-like features in a family of periplasmic pilus chaperones in bacteria.

Journal Article EMBO J · April 1992 Detailed structural analyses revealed a family of periplasmic chaperones in Gram-negative prokaryotes which are structurally and possibly evolutionarily related to the immunoglobulin superfamily and assist in the assembly of adhesive pili. The members of t ... Full text Link to item Cite

P pili in uropathogenic E. coli are composite fibres with distinct fibrillar adhesive tips.

Journal Article Nature · March 19, 1992 Escherichia coli is a frequent cause of several common bacterial infections in humans and animals, including urinary tract infections, bacteraemia and bacteria-related diarrhoea and is also the main cause of neonatal meningitis. Microbial attachment to sur ... Full text Link to item Cite

Immunoglobulin-like PapD chaperone caps and uncaps interactive surfaces of nascently translocated pilus subunits.

Journal Article Proc Natl Acad Sci U S A · December 1, 1991 Molecular chaperones are found in the cytoplasm of bacteria and in various cellular compartments in eukaryotes to maintain proteins in nonnative conformations that permit their secretion across membranes or assembly into oligomeric structures. Virtually no ... Full text Link to item Cite

Trimethoprim resistance in Haemophilus influenzae is due to altered dihydrofolate reductase(s).

Journal Article Biochem J · March 15, 1991 We characterized a highly purified preparation of the chromosomally encoded dihydrofolate reductase (DHFR) from a trimethoprim-susceptible (Tmp8; strain MAP) and two trimethoprim-resistant (TmpR) strains (MAP/47 and MAP/42) of Haemophilus influenzae. The e ... Link to item Cite

Contribution of a 28-kilodalton membrane protein to the virulence of Haemophilus influenzae.

Journal Article Infect Immun · February 1991 A Haemophilus influenzae b (Hib) membrane protein with a molecular mass of 28 kDa bound polyclonal antisera raised against a highly purified Hib fimbrial subunit. We cloned the gene encoding this protein and found that the gene was expressed in Escherichia ... Full text Link to item Cite