scholarly journals Alanylated lipoteichoic acid primer in Bacillus subtilis

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 155 ◽  
Author(s):  
Yu Luo
Keyword(s):  
Bacillus Subtilis ◽  
Lipoteichoic Acid ◽  
Head Group ◽  
Host Immune System ◽  
Type I ◽  
Bacterial Survival ◽  
Gram Positive Bacteria ◽  
Type Iv ◽  
Glycolipid Anchor ◽  
Group D

Lipoteichoic acid is a major lipid-anchored polymer in Gram-positive bacteria such asBacillus subtilis. This polymer typically consists of repeating phosphate-containing units and therefore has a predominant negative charge. The repeating units are attached to a glycolipid anchor which has a diacylglycerol (DAG) moiety attached to a dihexopyranose head group. D-alanylation is known as the major modification of type I and type IV lipoteichoic acids, which partially neutralizes the polymer and plays important roles in bacterial survival and resistance to the host immune system. The biosynthesis pathways of the glycolipid anchor and lipoteichoic acid have been fully characterized. However, the exact mechanism of D-alanyl transfer from the cytosol to cell surface lipoteichoic acid remains unclear. Here I report the use of mass spectrometry in the identification of possible intermediate species in the biosynthesis and D-alanylation of lipoteichoic acid: the glycolipid anchor, nascent lipoteichoic acid primer with one phosphoglycerol unit, as well as mono- and di-alanylated forms of the lipoteichoic acid primer. Monitoring these species as well as the recently reported D-alanyl-phosphatidyl glycerol should aid in shedding light on the mechanism of the D-alanylation pathway of lipoteichoic acid.

scholarly journals Alanylated lipoteichoic acid primer in Bacillus subtilis

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 155 ◽  
Author(s):  
Yu Luo
Keyword(s):  
Bacillus Subtilis ◽  
Negative Charge ◽  
Lipoteichoic Acid ◽  
Head Group ◽  
Host Immune System ◽  
Bacterial Survival ◽  
Intermediate Species ◽  
Gram Positive Bacteria ◽  
Glycolipid Anchor ◽  
Group D

Lipoteichoic acid is a major lipid-anchored polymer in Gram-positive bacteria such asBacillus subtilis. This polymer typically consists of repeating phosphoglycerol or phosphoribitol units and therefore has a predominant negative charge. The repeating units are attached to a glycolipid anchor which has a diacylglycerol (DAG) moiety attached to a dihexopyranose head group. D-alanylation is known as the major modification of lipoteichoic acid, which partially neutralizes the polymer and plays important roles in bacterial survival and resistance to the host immune system. The biosynthesis pathways of the glycolipid anchor and lipoteichoic acid have been fully characterized. However, the exact mechanism of D-alanyl transfer from the cytosol to cell surface lipoteichoic acid remains unclear. Here I report the use of mass spectrometry in the identification of intermediate species in the biosynthesis and D-alanylation of lipoteichoic acid: the glycolipid anchor, nascent lipoteichoic acid primer with one phosphoglycerol unit, as well as mono- and di-alanylated forms of the lipoteichoic acid primer. Monitoring these species as well as the recently reported D-alanyl-phosphatidyl glycerol would aid in shedding light on the mechanism of the D-alanylation pathway of lipoteichoic acid.

scholarly journals Streptococcus pneumoniae, S. mitis, and S. oralis produce a phosphatidylglycerol-dependent, ltaS-independent glycerophosphate-linked glycolipid

2020 ◽  
Author(s):  
Yahan Wei ◽  
Luke R. Joyce ◽  
Ashley M. Wall ◽  
Ziqiang Guan ◽  
Kelli L. Palmer
Keyword(s):  
Streptococcus Pneumoniae ◽  
Lipoteichoic Acid ◽  
Growth Defect ◽  
Type I ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Type Iv ◽  
Biosynthetic Precursor ◽  
Increased Sensitivity ◽  
Host Microbe Interactions

AbstractLipoteichoic acid (LTA) is a cell surface polymer of Gram-positive bacteria. LTA participates in host-microbe interactions including modulation of host immune reactions. It was previously reported that the major human pathogen Streptococcus pneumoniae and the closely related oral commensals S. mitis and S. oralis produce Type IV LTAs. Herein, using liquid chromatography/mass spectrometry (LC/MS)-based lipidomic analysis, we found that in addition to Type IV LTA biosynthetic precursors, S. mitis, S. oralis, and S. pneumoniae also produce glycerophosphate (Gro-P)-linked dihexosyl-diacylglycerol (DAG), which is a biosynthetic precursor of Type I LTA. Mutants in cdsA and pgsA produce dihexosyl-DAG but lack (Gro-P)-dihexosyl-DAG, indicating that the Gro-P moiety is derived from phosphatidylglycerol (PG), whose biosynthesis requires these genes. S. mitis, but neither S. pneumoniae nor S. oralis, encodes an ortholog of the PG-dependent Type I LTA synthase, ltaS. By heterologous expression analyses, we confirmed that S. mitis ltaS confers poly-(Gro-P) synthesis in both Escherichia coli and Staphylococcus aureus, and that S. mitis ltaS can rescue the severe growth defect of a S. aureus ltaS mutant. However, despite these observations, we do not detect a poly-(Gro-P) polymer in S. mitis using an anti-Type I LTA antibody. Moreover, (Gro-P)-linked dihexosyl-DAG is still synthesized by a S. mitis ltaS mutant, demonstrating that S. mitis LtaS does not catalyze the transfer of Gro-P from PG to dihexosyl-DAG. Finally, a S. mitis ltaS mutant has increased sensitivity to human serum, demonstrating that ltaS confers a beneficial but currently undefined function in S. mitis. Overall, our results demonstrate that S. mitis, S. pneumoniae, and S. oralis produce a (Gro-P)-linked glycolipid via a PG-dependent, ltaS-independent mechanism.ImportanceLTA is an important cell wall component synthesized by Gram-positive bacteria. Disruption of LTA production can confer severe physiological defects and attenuation of virulence. We report here the detection of a biosynthetic precursor of Type I LTA, in addition to the previously characterized Type IV LTA, in the total lipid extracts of S. pneumoniae, S. oralis, and S. mitis. Our results indicate that a novel mechanism is responsible for producing the Type I LTA intermediate. Our results are significant because they identify a novel feature of S. pneumoniae, S. oralis, and S. mitis glycolipid biology.

scholarly journals Protection from Lethal Gram-Positive Infection by Macrophage Scavenger Receptor–Dependent Phagocytosis

2000 ◽  
Vol 191 (1) ◽  
pp. 147-156 ◽  
Author(s):  
Christian A. Thomas ◽  
Yongmei Li ◽  
Tatsuhiko Kodama ◽  
Hiroshi Suzuki ◽  
Samuel C. Silverstein ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Critical Role ◽  
Scavenger Receptor ◽  
Lipoteichoic Acid ◽  
Peritoneal Macrophages ◽  
Type I ◽  
Dependent Manner ◽  
Gram Positive ◽  
Gram Positive Bacteria

Infections with gram-positive bacteria are a major cause of morbidity and mortality in humans. Opsonin-dependent phagocytosis plays a major role in protection against and recovery from gram-positive infections. Inborn and acquired defects in opsonin generation and/or recognition by phagocytes are associated with an increased susceptibility to bacterial infections. In contrast, the physiological significance of opsonin-independent phagocytosis is unknown. Type I and II class A scavenger receptors (SR-AI/II) recognize a variety of polyanions including bacterial cell wall products such as lipopolysaccharide (LPS) and lipoteichoic acid (LTA), suggesting a role for SR-AI/II in innate immunity to bacterial infections. Here, we show that SR-AI/II–deficient mice (MSR-A−/−) are more susceptible to intraperitoneal infection with a prototypic gram-positive pathogen, Staphylococcus aureus, than MSR-A+/+ control mice. MSR-A−/− mice display an impaired ability to clear bacteria from the site of infection despite normal killing of S. aureus by neutrophils and die as a result of disseminated infection. Opsonin-independent phagocytosis of gram-positive bacteria by MSR-A−/− macrophages is significantly decreased although their phagocytic machinery is intact. Peritoneal macrophages from control mice phagocytose a variety of gram-positive bacteria in an SR-AI/II–dependent manner. Our findings demonstrate that SR-AI/II mediate opsonin-independent phagocytosis of gram-positive bacteria, and provide the first evidence that opsonin-independent phagocytosis plays a critical role in host defense against bacterial infections in vivo.

scholarly journals A Crustin from Hydrothermal Vent Shrimp: Antimicrobial Activity and Mechanism

Marine Drugs ◽  
2021 ◽  
Vol 19 (3) ◽  
pp. 176
Author(s):  
Yujian Wang ◽  
Jian Zhang ◽  
Yuanyuan Sun ◽  
Li Sun
Keyword(s):  
Antimicrobial Activity ◽  
Deep Sea ◽  
Hydrothermal Vent ◽  
Binding Capacity ◽  
Lipoteichoic Acid ◽  
Type I ◽  
Disulfide Linkage ◽  
Structure Damage ◽  
Gram Positive Bacteria ◽  
Bacterial Binding

Crustin is a type of antimicrobial peptide and plays an important role in the innate immunity of arthropods. We report here the identification and characterization of a crustin (named Crus1) from the shrimp Rimicaris sp. inhabiting the deep-sea hydrothermal vent in Manus Basin (Papua New Guinea). Crus1 shares the highest identity (51.76%) with a Type I crustin of Penaeus vannamei and possesses a whey acidic protein (WAP) domain, which contains eight cysteine residues that form the conserved ‘four-disulfide core’ structure. Recombinant Crus1 (rCrus1) bound to peptidoglycan and lipoteichoic acid, and effectively killed Gram-positive bacteria in a manner that was dependent on pH, temperature, and disulfide linkage. rCrus1 induced membrane leakage and structure damage in the target bacteria, but had no effect on bacterial protoplasts. Serine substitution of each of the 8 Cys residues in the WAP domain did not affect the bacterial binding capacity but completely abolished the bactericidal activity of rCrus1. These results provide new insights into the characteristic and mechanism of the antimicrobial activity of deep sea crustins.

scholarly journals Localization and expression of the Bacillus subtilis dl-endopeptidase LytF are influenced by mutations in LTA synthases and glycolipid anchor synthetic enzymes

Microbiology ◽  
2014 ◽  
Vol 160 (12) ◽  
pp. 2639-2649 ◽  
Author(s):  
Yuuka Kiriyama ◽  
Kazuya Yazawa ◽  
Tatsuhito Tanaka ◽  
Ritsuko Yoshikawa ◽  
Hisaya Yamane ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Cell Separation ◽  
Vegetative Cell ◽  
Transcriptional Activity ◽  
Immunofluorescence Microscopy ◽  
Lipoteichoic Acid ◽  
Synthetic Enzymes ◽  
Principal Role ◽  
Artificial Induction ◽  
Glycolipid Anchor

Bacillus subtilis LytF plays a principal role in cell separation through its localization at the septa and poles on the vegetative cell surface. In this study, we found that a mutation in a major lipoteichoic acid (LTA) synthase gene – ltaS – results in a considerable reduction in the σD-dependent transcription of lytF. The lytF transcription was also reduced in mutants that affected glycolipid anchor biosynthesis. Immunofluorescence microscopy revealed that both the numbers of cells expressing LytF and the LytF foci in these mutants were decreased. In addition, the transcriptional activity of lytF was almost abolished in the double (ltaS yfnI), triple (ltaS yfnI yqgS), and quadruple (ltaS yfnI yqgS yvgJ) mutants during vegetative growth. Cell separation defects in these mutants were partially restored with artificial expression of LytF. Interestingly, when lytF transcription was induced in the ltaS single or multiple mutants, LytF was localized not only at the septum, but also along the sidewall. The amounts of LytF bound to cell wall in the single (ltaS) and double (ltaS yfnI) mutants gradually increased as compared with that in the WT strain, and those in the triple (ltaS yfnI yqgS) and quadruple mutants were almost similar to that in the double mutant. Moreover, reduction of the lytF transcription and chained cell morphology in the ltaS mutant were completely restored with artificial induction of the yqgS gene. These results strongly suggest that LTA influences the temporal, σD-dependent transcription of lytF and is an additional inhibitory component to the vegetative cell separation enzyme LytF.

scholarly journals Stents in the femoropopliteal territory: prevalence of fractures and their consequences

2020 ◽  
Vol 47 ◽  
Author(s):  
MARCELO DE AZEVEDO DAHER ◽  
GAUDENCIO ESPINOSA LOPEZ ◽  
PEDRO VAZ DUARTE
Keyword(s):  
Arterial Disease ◽  
Type I ◽  
X Rays ◽  
Type Iv ◽  
C 50 ◽  
Group B ◽  
Type V ◽  
Revascularization Procedures ◽  
Group D ◽  
Arterial Patency

ABSTRACT Endovascular treatment for femoropopliteal arterial disease has made revascularization procedures less invasive, but the self-expanding stents used can suffer great wear in arteries with extreme mobility. Objective: to evaluate the prevalence of fractures in stents implanted in the femoropopliteal segment, to identify predisposing factors and consequences on arterial patency. Method: between March and June 2019, thirty patients previously operated for femoropopliteal obstruction underwent stent X-rays in anteroposterior and lateral views to detect fractures and Doppler to analyze arterial patency. Results: we observed 12 cases with fractures (33.3%): 1 type I (2.8%), 3 type II (8.3%), 5 type III (13.9%), 3 type IV (8.3%) and no type V. According to the TASC II we had 1 in group B (8.3%), 6 in group C (50%) and 5 in group D (41.6%) p <0.004. The number of stents per limb was 3.1 (± 1.3) in cases of fracture versus 2.3 (± 1.3) in cases without fracture (p = 0.08). The extension was 274.17mm (± 100.94) in cases of fracture and 230.83mm (± 135.44) in cases without fracture (p = 0.29). On Doppler we had: 17 patients (47.2%) without stenosis, 9 patients (25%) with stenosis> 50% and 10 patients (27.8%) with occlusion (p = 0.37). There was no correlation between fracture and arterial obstruction (p = 0.33). Conclusion: stent fractures are a frequent finding in the femoropopliteal area (33.3%), being more prevalent in cases of more advanced disease (C and D). There was no association between the finding of fracture and arterial obstruction.

scholarly journals Commensal Streptococcus mitis produces two different lipoteichoic acids of type I and type IV

2021 ◽  
Author(s):  
Nicolas Gisch ◽  
Katharina Peters ◽  
Simone Thomsen ◽  
Waldemar Vollmer ◽  
Dominik Schwudke ◽  
...  
Keyword(s):  
Lipoteichoic Acid ◽  
Opportunistic Pathogen ◽  
Type I ◽  
Beta Lactam ◽  
Viridans Streptococci ◽  
Glycerol Phosphate ◽  
Streptococcus Mitis ◽  
Antibiotic Resistant ◽  
Type Iv ◽  
High Level

The opportunistic pathogen Streptococcus mitis possesses, like other members of the Mitis group of viridans streptococci, phosphorylcholine (P-Cho)-containing teichoic acids (TAs) in its cell wall. Bioinformatic analyses predicted the presence of TAs that are almost identical with those identified in the pathogen S. pneumoniae, but a detailed analysis of S. mitis lipoteichoic acid (LTA) was not performed to date. Here we determined the structures of LTA from two S. mitis strains, the high-level beta-lactam and multiple antibiotic resistant strain B6 and the penicillin-sensitive strain NCTC10712. In agreement with bioinformatic predictions we found that the structure of one LTA (type IV) was like pneumococcal LTA, except the exchange of a glucose moiety with a galactose within the repeating units. Further genome comparisons suggested that the majority of S. mitis strains should contain the same type IV LTA as S. pneumoniae, providing a more complete understanding of the biosynthesis of these P-Cho-containing TAs in members of the Mitis group of streptococci. Remarkably, we observed besides type IV LTA an additional polymer belonging to LTA type I in both investigated S. mitis strains. This LTA consists of β-galactofuranosyl-(1,3)-diacylglycerol as glycolipid anchor and a poly-glycerol-phosphate chain at the O-6 position of the furanosidic galactose. Hence, these bacteria are capable of synthesizing two different LTA polymers, most likely produced by distinct biosynthesis pathways. Our bioinformatics analysis revealed the prevalence of the LTA synthase LtaS, most probably responsible for the second LTA version (type I), amongst S. mitis and S. pseudopneumoniae strains.

scholarly journals GtcA is required for LTA glycosylation in Listeria monocytogenes serovar 1/2a and Bacillus subtilis

2019 ◽  
Author(s):  
Jeanine Rismondo ◽  
Talal F. M. Haddad ◽  
Yang Shen ◽  
Martin J. Loessner ◽  
Angelika Gründling
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis ◽  
Listeria Monocytogenes ◽  
Teichoic Acid ◽  
Lipoteichoic Acid ◽  
Wall Teichoic Acid ◽  
Gram Positive Bacteria ◽  
Cell Wall Polymers ◽  
Galactose Residue

ABSTRACTThe cell wall polymers wall teichoic acid (WTA) and lipoteichoic acid (LTA) are often modified with glycosyl and D-alanine residues. Recent studies have shown that a three-component glycosylation system is used for the modification of LTA in several Gram-positive bacteria including Bacillus subtilis and Listeria monocytogenes. In the L. monocytogenes 1/2a strain 10403S, the cytoplasmic glycosyltransferase GtlA is thought to use UDP-galactose to produce the C55-P-galactose lipid intermediate, which is transported across the membrane by an unknown flippase. Next, the galactose residue is transferred onto the LTA backbone on the outside of the cell by the glycosyltransferase GtlB. Here we show that GtcA is necessary for the glycosylation of LTA in L. monocytogenes 10403S and B. subtilis 168 and we hypothesize that these proteins act as C55-P-sugar flippases. With this we revealed that GtcA is involved in the glycosylation of both teichoic acid polymers in L. monocytogenes 10403S, namely WTA with N-acetylglucosamine and LTA with galactose residues. These findings indicate that the L. monocytogenes GtcA protein can act on different C55-P-sugar intermediates. Further characterization of GtcA in L. monocytogenes led to the identification of residues essential for its overall function as well as residues, which predominately impact WTA or LTA glycosylation.GRAPHICAL ABSTRACT

scholarly journals Lipoteichoic Acid Is a Major Component of the Bacillus subtilis Periplasm

2008 ◽  
Vol 190 (22) ◽  
pp. 7414-7418 ◽  
Author(s):  
Valério R. F. Matias ◽  
Terry J. Beveridge
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis ◽  
Lipoteichoic Acid ◽  
Periplasmic Space ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Cryo Electron Microscopy ◽  
Resolution Observation ◽  
Positively Charged Gold Nanoparticles ◽  
Positively Charged

ABSTRACT Cryo-electron microscopy (cryo-EM) of frozen-hydrated specimens allows high-resolution observation of structures in optimally preserved samples. In gram-positive bacteria, this method reveals the presence of a periplasmic space between the plasma membrane and an often differentiated cell wall matrix. Since virtually nothing is known about the composition of its constituent matter (i.e., the periplasm), it is still unclear what structures (or mechanism) sustain a gram-positive periplasmic space. Here we have used cryo-EM of frozen-hydrated sections in combination with various labels to probe the model gram-positive organism Bacillus subtilis for major periplasmic components. Incubation of cells with positively charged gold nanoparticles showed almost similar levels of gold binding to the periplasm and the cell wall. On cells whose cell walls were enzymatically hydrolyzed (i.e., on protoplasts), a surface diffuse layer extending ∼30 nm from the membrane was revealed. The thickness and density of this layer were not significantly altered after treatment with a nonspecific protease, whereas it was labeled with anti-lipoteichoic acid (LTA) antibodies conjugated to nanogold. Further, the LTA layer spans most of the thickness of the periplasmic space, which strongly suggests that LTA is a major component of the B. subtilis periplasm.

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