scholarly journals A Quorum Sensing-Regulated Protein Binds Cell Wall Components and Enhances Lysozyme Resistance inStreptococcus pyogenes

2018 ◽  
Vol 200 (11) ◽  
Author(s):  
Artemis Gogos ◽  
Juan Cristobal Jimenez ◽  
Jennifer C. Chang ◽  
Reid V. Wilkening ◽  
Michael J. Federle
Keyword(s):  
Cell Wall ◽  
Quorum Sensing ◽  
Cell Surface ◽  
Bacterial Cell ◽  
Host Factor ◽  
Molecular Architecture ◽  
Gas Cell ◽  
Content Type ◽  
Bacterial Cell Surface ◽  
Positively Charged

ABSTRACTThe Rgg2/3 quorum sensing (QS) system is conserved among all sequenced isolates of group AStreptococcus(GAS;Streptococcus pyogenes). The molecular architecture of the system consists of a transcriptional activator (Rgg2) and a transcriptional repressor (Rgg3) under the control of autoinducing peptide pheromones (SHP2 and SHP3). Activation of the Rgg2/3 pathway leads to increases in biofilm formation and resistance to the bactericidal effects of the host factor lysozyme. In this work, we show that deletion of a small gene,spy49_0414c, abolished both phenotypes in response to pheromone signaling. The gene encodes a small, positively charged, secreted protein, referred to as StcA. Analysis of recombinant StcA showed that it can directly interact with GAS cell wall preparations containing phosphodiester-linked carbohydrate polymers but not with preparations devoid of them. Immunofluorescence microscopy detected antibody against StcA bound to the surface of paraformaldehyde-fixed wild-type cells. Expression of StcA in bacterial culture induced a shift in the electrostatic potential of the bacterial cell surface, which became more positively charged. These results suggest that StcA promotes phenotypes by way of ionic interactions with the GAS cell wall, most likely with negatively charged cell wall-associated polysaccharides.IMPORTANCEThis study focuses on a small protein, StcA, that is expressed and secreted under induction of Rgg2/3 QS, ionically associating with negatively charged domains on the cell surface. These data present a novel mechanism of resistance to the host factor lysozyme by GAS and have implications in the relevance of this circuit in the interaction between the bacterium and the human host that is mediated by the bacterial cell surface.

scholarly journals Lectin Microarray Reveals Binding Profiles of Lactobacillus casei Strains in a Comprehensive Analysis of Bacterial Cell Wall Polysaccharides

2011 ◽  
Vol 77 (13) ◽  
pp. 4539-4546 ◽  
Author(s):  
Emi Yasuda ◽  
Hiroaki Tateno ◽  
Jun Hirabarashi ◽  
Tohru Iino ◽  
Tomoyuki Sako
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Bacterial Cell ◽  
Lactobacillus Casei ◽  
Lectin Binding ◽  
Bacterial Strains ◽  
Cell Wall Polysaccharides ◽  
Content Type ◽  
Lectin Microarray ◽  
Bacterial Cell Surface

ABSTRACTWe previously showed a pivotal role of the polysaccharide (PS) moiety in the cell wall of theLactobacillus caseistrain Shirota (YIT 9029) as a possible immune modulator (E. Yasuda M. Serata, and T. Sako, Appl. Environ. Microbiol. 74:4746-4755, 2008). To distinguish PS structures on the bacterial cell surface of individual strains in relation to their activities, it would be useful to have a rapid and high-throughput methodology. Recently, a new technique called lectin microarray was developed for rapid profiling of glycosylation in eukaryotic polymers and cell surfaces. Here, we report on the development of a simple and sensitive method based on this technology for direct analysis of intact bacterial cell surface glycomes. The method involves labeling bacterial cells with SYTOX Orange before incubation with the lectin microarray. After washing, bound cells are directly detected using an evanescent-field fluorescence scanner in a liquid phase. Using this method, we compared the cell surface glycomes from 16 different strains ofL. casei. The patterns of lectin-binding affinity of most strains were found to be unique. There appears to be two types of lectin-binding profiles: the first is characterized by a few lectins, and the other is characterized by multiple lectins with different specificities. We also showed a dramatic change in the lectin-binding profile of a YIT 9029 derivative with a mutation in thecps1Cgene, encoding a putative glycosyltransferase. In conclusion, the developed technique provided a novel strategy for rapid profiling and, more importantly, differentiating numerous bacterial strains with relevance to the biological functions of PS.

scholarly journals Proton-Dependent Gating and Proton Uptake by Wzx Support O-Antigen-Subunit Antiport Across the Bacterial Inner Membrane

mBio ◽  
2013 ◽  
Vol 4 (5) ◽  
Author(s):  
Salim T. Islam ◽  
Paul D. W. Eckford ◽  
Michelle L. Jones ◽  
Timothy Nugent ◽  
Christine E. Bear ◽  
...  
Keyword(s):  
Cell Surface ◽  
Bacterial Cell ◽  
Electrical Potential ◽  
Three Dimensional ◽  
Structural Data ◽  
Inner Membrane ◽  
Content Type ◽  
Bacterial Cell Surface ◽  
Repeat Units ◽  
Dependent Transport

ABSTRACTWzx flippases are crucial for bacterial cell surface polysaccharide assembly as they transport undecaprenyl pyrophosphate-linked sugar repeat units from the cytoplasmic to the periplasmic leaflets of the inner membrane (IM) for final assembly. Our recently reported three-dimensional (3D) model structure of Wzx fromPseudomonas aeruginosaPAO1 (WzxPa) displayed a cationic internal vestibule and functionally essential acidic amino acids within transmembrane segment bundles. Herein, we examined the intrinsic transport function of WzxPafollowing its purification and reconstitution in phospholipid liposomes. WzxPawas capable of mediating anion flux, consistent with its cationic interior. This flux was electrogenic and modified by extraliposomal pH. Mutation of the above-mentioned acidic residues (E61, D269, and D359) reduced proton (H+)-modified anion flux, showing the role of these amino acid side chains in H+-dependent transport. Wzx also mediated acidification of the proteoliposome interior in the presence of an outward anion gradient. These results indicate H+-dependent gating and H+uptake by WzxPaand allow for the first H+-dependent antiport mechanism to be proposed for lipid-linked oligosaccharide translocation across the bacterial IM.IMPORTANCEMany bacterial cell surface polysaccharides that are important for survival and virulence are synthesized at the periplasmic leaflet of the inner membrane (IM) using precursors produced in the cytoplasm. Wzx flippases are responsible for translocation of lipid-linked sugar repeat units across the IM and had been previously suggested to simply facilitate passive substrate diffusion. Through our characterization of purified Wzx in a reconstitution system described herein, we have observed protein-dependent intrinsic transport producing a change in the electrical potential of the system, with H+identified as the coupling ion. These results provide the first evidence for coupled (i.e., secondary active) transport by these proteins and, in conjunction with structural data, allow for an antiport mechanism to be proposed for the directed transport of lipid-linked sugar substrates across the IM. These findings bring our understanding of lipid-linked polysaccharide transporter proteins more in line with the efflux pumps to which they are evolutionarily related.

scholarly journals The LuxI/LuxR-Type Quorum Sensing System Regulates Degradation of Polycyclic Aromatic Hydrocarbons via Two Mechanisms

2020 ◽  
Vol 21 (15) ◽  
pp. 5548
Author(s):  
Zhiliang Yu ◽  
Zeyu Hu ◽  
Qimiao Xu ◽  
Mengting Zhang ◽  
Nate Yuan ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Quorum Sensing ◽  
Cell Surface ◽  
Aromatic Hydrocarbons ◽  
Bacterial Cell ◽  
Regulatory Gene ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Bacterial Cell Surface ◽  
Polycyclic Aromatic

Members of the Sphingomonadales are renowned for their ability to degrade polycyclic aromatic hydrocarbons (PAHs). However, little is known about the regulatory mechanisms of the degradative pathway. Using cross-feeding bioassay, a functional LuxI/LuxR-type acyl-homoserine lactone (AHL)-mediated quorum sensing (QS) system was identified from Croceicoccus naphthovorans PQ-2, a member of the order Sphingomonadales. Inactivation of the QS system resulted in a significant decrease in PAHs degradation. The QS system positively controlled the expression of three PAH-degrading genes (ahdA1e, xylE and xylG) and a regulatory gene ardR, which are located on the large plasmid. Interestingly, the transcription levels of these three PAH-degrading genes were significantly down-regulated in the ardR mutant. In addition, bacterial cell surface hydrophobicity and cell morphology were altered in the QS-deficient mutant. Therefore, the QS system in strain PQ-2 positively regulates PAH degradation via two mechanisms: (i) by induction of PAH-degrading genes directly and/or indirectly; and (ii) by an increase of bacterial cell surface hydrophobicity. The findings of this study improve our understanding of how the QS system influences the degradation of PAHs, therefore facilitating the development of new strategies for the bioremediation of PAHs.

The structure of secondary cell wall polymers: how Gram-positive bacteria stick their cell walls together

Microbiology ◽  
2005 ◽  
Vol 151 (3) ◽  
pp. 643-651 ◽  
Author(s):  
Christina Schäffer ◽  
Paul Messner
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Bacterial Cell ◽  
Secondary Cell Wall ◽  
Chemical Study ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Bacterial Cell Surface ◽  
Cell Wall Polymers ◽  
Structural Principles

The cell wall of Gram-positive bacteria has been a subject of detailed chemical study over the past five decades. Outside the cytoplasmic membrane of these organisms the fundamental polymer is peptidoglycan (PG), which is responsible for the maintenance of cell shape and osmotic stability. In addition, typical essential cell wall polymers such as teichoic or teichuronic acids are linked to some of the peptidoglycan chains. In this review these compounds are considered as ‘classical’ cell wall polymers. In the course of recent investigations of bacterial cell surface layers (S-layers) a different class of ‘non-classical’ secondary cell wall polymers (SCWPs) has been identified, which is involved in anchoring of S-layers to the bacterial cell surface. Comparative analyses have shown considerable differences in chemical composition, overall structure and charge behaviour of these SCWPs. This review discusses the progress that has been made in understanding the structural principles of SCWPs, which may have useful applications in S-layer-based ‘supramolecular construction kits' in nanobiotechnology.

scholarly journals Bacterial Cell Surface Damage Due to Centrifugal Compaction

2011 ◽  
Vol 78 (1) ◽  
pp. 120-125 ◽  
Author(s):  
Brandon W. Peterson ◽  
Prashant K. Sharma ◽  
Henny C. van der Mei ◽  
Henk J. Busscher
Keyword(s):  
Zeta Potential ◽  
Cell Surface ◽  
Surface Properties ◽  
Bacterial Cell ◽  
Surface Damage ◽  
Deposition Rates ◽  
Content Type ◽  
Cell Surface Properties ◽  
Bacterial Cell Surface ◽  
Initial Deposition

ABSTRACTCentrifugal damage has been known to alter bacterial cell surface properties and interior structures, including DNA. Very few studies exist on bacterial damage caused by centrifugation because of the difficulty in relating centrifugation speed and container geometry to the damage caused. Here, we provide a simple, versatile method of analysis for describing the compaction of bacteria during centrifugation based on a proposed centrifugation coefficient,C. Values ofCcan be related to different bacterial cell surface properties. Changing the geometry of the centrifugation container or centrifugation speeds changed the value ofCsignificantly. Initial deposition rates ofStaphylococcus aureusATCC 12600 to a glass surface decayed exponentially from 4,217 to 1,478 cm−2s−1with increasingC, while the proportion of staphylococci with a zeta potential of around −15 mV decreased from 97 to 58%. These surface-sensitive parameters were used independently to derive a critical centrifugation coefficient (0.040), above which centrifugation was considered to impact the outcome of surface-sensitive experiments due to cell surface damage. The critical centrifugation coefficient could successfully predict staphylococcal cell surface damage, i.e., a significant change in initial deposition rate or zeta potential distribution, in 84% of all cases included here, whereas the centrifugation speed could predict damage in only 58% of all cases. Moreover, controlling the centrifugation coefficient within narrow limits over a series of experiments yielded 43% smaller standard deviations in initial staphylococcal deposition rates than with centrifugation at fixed speeds for replicate experiments.

scholarly journals Identification of Extracellular DNA-Binding Proteins in the Biofilm Matrix

mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Jeffrey S. Kavanaugh ◽  
Caralyn E. Flack ◽  
Jessica Lister ◽  
Erica B. Ricker ◽  
Carolyn B. Ibberson ◽  
...  
Keyword(s):  
Dna Binding ◽  
Cell Surface ◽  
Bacterial Cell ◽  
Binding Activity ◽  
Extracellular Dna ◽  
Bacterial Biofilms ◽  
Content Type ◽  
Bacterial Cell Surface ◽  
Dna Binding Activity ◽  
Biofilm Matrix

ABSTRACT We developed a new approach that couples Southwestern blotting and mass spectrometry to discover proteins that bind extracellular DNA (eDNA) in bacterial biofilms. Using Staphylococcus aureus as a model pathogen, we identified proteins with known DNA-binding activity and uncovered a series of lipoproteins with previously unrecognized DNA-binding activity. We demonstrated that expression of these lipoproteins results in an eDNA-dependent biofilm enhancement. Additionally, we found that while deletion of lipoproteins had a minimal impact on biofilm accumulation, these lipoprotein mutations increased biofilm porosity, suggesting that lipoproteins and their associated interactions contribute to biofilm structure. For one of the lipoproteins, SaeP, we showed that the biofilm phenotype requires the lipoprotein to be anchored to the outside of the cellular membrane, and we further showed that increased SaeP expression correlates with more retention of high-molecular-weight DNA on the bacterial cell surface. SaeP is a known auxiliary protein of the SaeRS system, and we also demonstrated that the levels of SaeP correlate with nuclease production, which can further impact biofilm development. It has been reported that S. aureus biofilms are stabilized by positively charged cytoplasmic proteins that are released into the extracellular environment, where they make favorable electrostatic interactions with the negatively charged cell surface and eDNA. In this work we extend this electrostatic net model to include secreted eDNA-binding proteins and membrane-attached lipoproteins that can function as anchor points between eDNA in the biofilm matrix and the bacterial cell surface. IMPORTANCE Many bacteria are capable of forming biofilms encased in a matrix of self-produced extracellular polymeric substances (EPS) that protects them from chemotherapies and the host defenses. As a result of these inherent resistance mechanisms, bacterial biofilms are extremely difficult to eradicate and are associated with chronic wounds, orthopedic and surgical wound infections, and invasive infections, such as infective endocarditis and osteomyelitis. It is therefore important to understand the nature of the interactions between the bacterial cell surface and EPS that stabilize biofilms. Extracellular DNA (eDNA) has been recognized as an EPS constituent for many bacterial species and has been shown to be important in promoting biofilm formation. Using Staphylococcus aureus biofilms, we show that membrane-attached lipoproteins can interact with the eDNA in the biofilm matrix and promote biofilm formation, which suggests that lipoproteins are potential targets for novel therapies aimed at disrupting bacterial biofilms.

scholarly journals The N2N3 domains of ClfA, FnbpA, and FnbpB in Staphylococcus aureus bind to human complement factor H, and their antibodies enhance the bactericidal capability of human blood

2020 ◽  
Author(s):  
Xinrui Mao ◽  
Junghyun Kim ◽  
QingFeng Zhang ◽  
TingTing Jiang ◽  
Dong Ho Ahn ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Surface ◽  
Human Blood ◽  
Bacterial Cell ◽  
Regulatory Protein ◽  
Factor H ◽  
Complement Factor ◽  
Bacterial Cell Surface ◽  
Protein Factor

Abstract In the complement system, the opsonin C3b binds to the bacterial cell surface and mediates the opsonophagocytosis. However, the cell wall protein SdrE of Staphylococcus aureus inhibits the C3b activity by recruiting the complement regulatory protein factor H (fH). SdrE binds to fH via its N-terminal N2N3 domain, which are also found in six other staphylococcal cell wall proteins. In this study, we report that not only the N2N3 domain of SdrE but also those of ClfA, FnbpA, and FnbpB can bind to fH. When immobilized on a microplate, the N2N3 domains recruited fH and enhanced the factor I (fI)-mediated cleavage of C3b. When mixed with fH and S. aureus cells, the N2N3 domains inhibited the fH binding to S. aureus cells and reduced the fI-mediated C3b cleavage on the bacterial cell surface. The F(ab)′2 fragments of the rabbit N2N3 antibodies also inhibited the fH-binding to the S. aureus cell surface. When added to human blood, the N2N3 antibodies or the N2N3 domain proteins significantly increased the bactericidal activity. Based on these results, we conclude that, in S. aureus, not only SdrE but also ClfA, FnbpA, and FnbpB can contribute to the inhibition of C3b-mediated opsonophagocytosis.

Fe(iii)-complex mediated bacterial cell surface immobilization of eGFP and enzymes

2021 ◽  
Author(s):  
Lilin Feng ◽  
Liang Gao ◽  
Daniel F. Sauer ◽  
Yu Ji ◽  
Haiyang Cui ◽  
...  
Keyword(s):  
Cell Surface ◽  
Bacterial Cell ◽  
Surface Immobilization ◽  
E Coli ◽  
Bacterial Cell Surface ◽  
Reversible Method

A facile and reversible method to immobilize His6-tagged proteins on the E. coli cell surface through the formation of an Fe(iii)-complex.

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