scholarly journals High-resolution analysis of the peptidoglycan composition inStreptomyces coelicolor

2018 ◽  
Author(s):  
Lizah T. van der Aart ◽  
Gerwin K. Spijksma ◽  
Amy Harms ◽  
Waldemar Vollmer ◽  
Thomas Hankemeier ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycelial Growth ◽  
Antibiotic Production ◽  
Hydrolytic Enzymes ◽  
Morphological Differentiation ◽  
Model Organisms ◽  
Major Constituent ◽  
Single Spore ◽  
High Resolution Analysis ◽  
Cell Growth And Differentiation

ABSTRACTThe bacterial cell wall maintains cell shape and protects against bursting by the turgor. A major constituent of the cell wall is peptidoglycan (PG), which is continuously modified to allow cell growth and differentiation through the concerted activity of biosynthetic and hydrolytic enzymes. Streptomycetes are Gram-positive bacteria with a complex multicellular life style alternating between mycelial growth and the formation of reproductive spores. This involves cell-wall remodeling at apical sites of the hyphae during cell elongation and autolytic degradation of the vegetative mycelium during the onset of development and antibiotic production. Here, we show that there are distinct differences in the cross-linking and maturation of the PG between exponentially growing vegetative hyphae and the aerial hyphae that undergo sporulation. LC-MS/MS analysis identified over 80 different muropeptides, revealing that major PG hydrolysis takes place over the course of mycelial growth. Half of the dimers lack one of the disaccharide units in transition-phase cells, most likely due to autolytic activity. De-acetylation of MurNAc to MurN was particularly pronounced in spores, suggesting that MurN plays a role in spore development. Taken together, our work highlights dynamic and growth phase-dependent construction and remodeling of PG inStreptomyces.IMPORTANCEStreptomycetes are bacteria with a complex lifestyle, which are model organisms for bacterial multicellularity. From a single spore a large multigenomic, multicellular mycelium is formed, which differentiates to form spores. Programmed cell death is an important event during the onset of morphological differentiation. In this work we provide new insights into the changes in the peptidoglycan architecture over time, highlighting changes over the course of development and between growing mycelia and spores. This revealed dynamic changes in the peptidoglycan when the mycelia age, showing extensive PG hydrolysis and in particular an increase in the proportion of 3-3-cross-links. Additionally, we identified a muropeptide that is highly abundant specifically in spores, which may relate to dormancy and germination.

scholarly journals High-Resolution Analysis of the Peptidoglycan Composition inStreptomyces coelicolor

2018 ◽  
Vol 200 (20) ◽  
Author(s):  
Lizah T. van der Aart ◽  
Gerwin K. Spijksma ◽  
Amy Harms ◽  
Waldemar Vollmer ◽  
Thomas Hankemeier ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycelial Growth ◽  
Antibiotic Production ◽  
Hydrolytic Enzymes ◽  
Morphological Differentiation ◽  
Model Organisms ◽  
Major Constituent ◽  
Single Spore ◽  
Content Type ◽  
Liquid Chromatography Tandem Mass

ABSTRACTThe bacterial cell wall maintains cell shape and protects against bursting by turgor. A major constituent of the cell wall is peptidoglycan (PG), which is continuously modified to enable cell growth and differentiation through the concerted activity of biosynthetic and hydrolytic enzymes. Streptomycetes are Gram-positive bacteria with a complex multicellular life style alternating between mycelial growth and the formation of reproductive spores. This involves cell wall remodeling at apical sites of the hyphae during cell elongation and autolytic degradation of the vegetative mycelium during the onset of development and antibiotic production. Here, we show that there are distinct differences in the cross-linking and maturation of the PGs between exponentially growing vegetative hyphae and the aerial hyphae that undergo sporulation. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis identified over 80 different muropeptides, revealing that major PG hydrolysis takes place over the course of mycelial growth. Half of the dimers lacked one of the disaccharide units in transition-phase cells, most likely due to autolytic activity. The deacetylation of MurNAc to MurN was particularly pronounced in spores and strongly reduced in sporulation mutants with a deletion ofbldDorwhiG, suggesting that MurN is developmentally regulated. Altogether, our work highlights the dynamic and growth phase-dependent changes in the composition of the PG inStreptomyces.IMPORTANCEStreptomycetes are bacteria with a complex lifestyle and are model organisms for bacterial multicellularity. From a single spore, a large multigenomic multicellular mycelium is formed, which differentiates to form spores. Programmed cell death is an important event during the onset of morphological differentiation. In this work, we provide new insights into the changes in the peptidoglycan composition and over time, highlighting changes over the course of development and between growing mycelia and spores. This revealed dynamic changes in the peptidoglycan when the mycelia aged, with extensive peptidoglycan hydrolysis and, in particular, an increase in the proportion of 3-3 cross-links. Additionally, we identified a muropeptide that accumulates predominantly in the spores and may provide clues toward spore development.

scholarly journals The Cell Wall Hydrolytic NlpC/P60 Endopeptidases in Mycobacterial Cytokinesis: A Structural Perspective

Cells ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 609 ◽  
Author(s):  
Flavia Squeglia ◽  
Miguel Moreira ◽  
Alessia Ruggiero ◽  
Rita Berisio
Keyword(s):  
Cell Wall ◽  
Functional Data ◽  
Hydrolytic Enzymes ◽  
Diaminopimelic Acid ◽  
Major Constituent ◽  
Wall Material ◽  
Gene Encoding ◽  
Daughter Cells ◽  
Fine Regulation

In preparation for division, bacteria replicate their DNA and segregate the newly formed chromosomes. A division septum then assembles between the chromosomes, and the mother cell splits into two identical daughters due to septum degradation. A major constituent of bacterial septa and of the whole cell wall is peptidoglycan (PGN), an essential cell wall polymer, formed by glycan chains of β−(1-4)-linked-N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid (MurNAc), cross-linked by short peptide stems. Depending on the amino acid located at the third position of the peptide stem, PGN is classified as either Lys-type or meso-diaminopimelic acid (DAP)-type. Hydrolytic enzymes play a crucial role in the degradation of bacterial septa to split the cell wall material shared by adjacent daughter cells to promote their separation. In mycobacteria, a key PGN hydrolase, belonging to the NlpC/P60 endopeptidase family and denoted as RipA, is responsible for the degradation of septa, as the deletion of the gene encoding for this enzyme generates abnormal bacteria with multiple septa. This review provides an update of structural and functional data highlighting the central role of RipA in mycobacterial cytokinesis and the fine regulation of its catalytic activity, which involves multiple molecular partners.

SIGNIFICANCE OF ANTIBIOTIC PRODUCTION BY CEPHALOSPORIUM GRAMINEUM TO ITS SAPROPHYTIC SURVIVAL

1969 ◽  
Vol 49 (3) ◽  
pp. 235-246 ◽  
Author(s):  
G. W. Bruehl ◽  
R. L. Millar ◽  
Barry Cunfer
Keyword(s):  
Mycelial Growth ◽  
Selective Pressure ◽  
Wide Spectrum ◽  
Antibiotic Production ◽  
Selective Advantage ◽  
Potato Dextrose Agar ◽  
Selective Force ◽  
Single Spore ◽  
Cephalosporium Gramineum ◽  
Parasitic Phase

Of several hundred isolates of Cephalosporium gramineum from nature, all produced a wide-spectrum, antifungal antibiotic. In contrast, certain single-spore isolates from cultures maintained at 6 °C for 2–5 years on potato dextrose agar produced little or no antibiotic. This suggests that in nature a selective force acts to preserve antibiotic producers and to eliminate nonproducers.Selection pressure in favor of antibiotic producers apparently is not exerted in the parasitic phase, because both antibiotic producers and nonproducers are pathogenic. Mycelial growth rates do not give a selective advantage to antibiotic producers as they usually grow more slowly than do nonproducers. The antibiotic itself does not exert selective pressure on nonproducers since nonproducers are not inhibited in culture by producers.Antibiotic producers established in straw reduce the invasion of the straw in soil by other fungi more than do the nonproducers. These observations support the hypothesis that the antibiotic aids the survival of C. gramineum in its saprophytic phases, and that selection pressure in favor of antibiotic producers is probably exerted while the fungus is in the soil.

scholarly journals Cell Wall Hydrolases Affect Germination, Vegetative Growth, and Sporulation in Streptomyces coelicolor

2009 ◽  
Vol 191 (21) ◽  
pp. 6501-6512 ◽  
Author(s):  
Henry J. Haiser ◽  
Mary R. Yousef ◽  
Marie A. Elliot
Keyword(s):  
Cell Wall ◽  
Life Cycle ◽  
Vegetative Growth ◽  
Streptomyces Coelicolor ◽  
Hydrolytic Enzymes ◽  
In Silico Analysis ◽  
Cell Types ◽  
Complex Life Cycle ◽  
Cell Wall Remodeling ◽  
Cell Growth And Differentiation

ABSTRACT Peptidoglycan is a major cell wall constituent of gram-positive bacteria. It is a dynamic macromolecule that is actively remodeled to enable cell growth and differentiation through a tightly choreographed interplay of hydrolytic and biosynthetic enzyme activities. The filamentous bacterium Streptomyces coelicolor has a complex life cycle that likely requires considerable cell wall remodeling to enable both extension of vegetative hyphae and formation of differentiated cell types. In silico analysis of the S. coelicolor genome enabled identification of 56 candidate cell wall hydrolase genes. We found that seven of these genes shared a highly conserved 5′ untranslated region and were expressed during both vegetative growth and sporulation; four of these genes were selected for more extensive biochemical and biological characterization. The proteins encoded by these genes, termed RpfA, SwlA, SwlB, and SwlC, were confirmed to be hydrolytic enzymes, as they could efficiently cleave S. coelicolor cell walls. Phenotypic analyses revealed that these enzymes are important throughout development; deletion of each hydrolase gene resulted in a mutant strain that was heat sensitive, defective in spore formation, and either altered in vegetative growth or delayed in spore germination. Our results indicate that these enzymes play key roles at multiple stages in the growth and development of S. coelicolor, highlighting both the lack of redundancy in hydrolase activity and the importance of cell wall remodeling in the S. coelicolor life cycle.

Inactivation or amplification of the spa2 gene, encoding a potential stationary-phase regulator, affects differentiation in Streptomyces ambofaciens

1997 ◽  
Vol 43 (12) ◽  
pp. 1118-1125 ◽  
Author(s):  
Martine Aubert ◽  
Elisabeth Weber ◽  
Brigitte Gintz ◽  
Bernard Decaris ◽  
Keith F. Chater
Keyword(s):  
Stationary Phase ◽  
Antibiotic Production ◽  
Morphological Differentiation ◽  
Aerial Mycelium ◽  
Detectable Effect ◽  
Multicopy Plasmid ◽  
Gene Encoding ◽  
Wild Type Phenotype ◽  
Streptomyces Ambofaciens ◽  
Mycelial Development

The deduced product of the spa2 gene of Streptomyces ambofaciens is a homologue of RspA, involved in stationary-phase σs factor regulation in Escherichia coli. This suggests that Spa2 could play a part in stationary-phase-associated differentiation in S. ambofaciens. The disruption of spa2 led to reductions in aerial mycelial development and associated spore pigmentation. The mutant phenotype reverted to the wild-type phenotype when the disruption construct spontaneously excised. The spa2 disruption had no detectable effect on growth rates in different media or antibiotic production and resistance. When spa2 was placed on a multicopy plasmid, a severe defect in formation and pigmentation of aerial mycelium resulted. These results strongly suggest that Spa2 is involved in a complex manner in the morphological differentiation process.Key words: Streptomyces, differentiation, stationary-phase regulator.

scholarly journals Co-operative action by endo- and exo-β-(1→3)-glucanases from parasitic fungi in the degradation of cell-wall glucans of Sclerotinia sclerotiorum (Lib.) de Bary

1974 ◽  
Vol 140 (1) ◽  
pp. 47-55 ◽  
Author(s):  
David Jones ◽  
Alex. H. Gordon ◽  
John S. D. Bacon
Keyword(s):  
Cell Wall ◽  
Sclerotinia Sclerotiorum ◽  
Culture Filtrate ◽  
Cell Walls ◽  
Trichoderma Viride ◽  
Major Constituent ◽  
Coniothyrium Minitans ◽  
Parasitic Fungi ◽  
Complete Breakdown

1. Two fungi, Coniothyrium minitans Campbell and Trichoderma viride Pers. ex Fr., were grown on autoclaved crushed sclerotia of the species Sclerotinia sclerotiorum, which they parasitize. 2. in vitro the crude culture filtrates would lyse walls isolated from hyphal cells or the inner pseudoparenchymatous cells of the sclerotia, in which a branched β-(1→3)-β-(1→6)-glucan, sclerotan, is a major constituent. 3. Chromatographic fractionation of the enzymes in each culture filtrate revealed the presence of several laminarinases, the most active being an exo-β-(1→3)-glucanase, known from previous studies to attack sclerotan. Acting alone this brought about a limited degradation of the glucan, but the addition of fractions containing an endo-β-(1→3)-glucanase led to almost complete breakdown. A similar synergism between the two enzymes was found in their lytic action on cell walls. 4. When acting alone the endo-β-(1→3)-glucanase had a restricted action, the products including a trisaccharide, tentatively identified as 62-β-glucosyl-laminaribiose. 5. These results are discussed in relation to the structure of the cell walls and of their glucan constituents.

scholarly journals Receptor Internalization in Yeast Requires the Tor2-Rho1 Signaling Pathway

2003 ◽  
Vol 14 (11) ◽  
pp. 4676-4684 ◽  
Author(s):  
Amy K.A. deHart ◽  
Joshua D. Schnell ◽  
Damian A. Allen ◽  
Ju-Yun Tsai ◽  
Linda Hicke
Keyword(s):  
Cell Wall ◽  
Cell Cycle Progression ◽  
Structural Integrity ◽  
Nutrient Sensing ◽  
Receptor Internalization ◽  
Cell Integrity ◽  
Nucleotide Exchange ◽  
Nucleotide Exchange Factor ◽  
Similar Phenotype ◽  
Cell Growth And Differentiation

Efficient internalization of proteins from the cell surface is essential for regulating cell growth and differentiation. In a screen for yeast mutants defective in ligand-stimulated internalization of the α-factor receptor, we identified a mutant allele of TOR2, tor2G2128R. Tor proteins are known to function in translation initiation and nutrient sensing and are required for cell cycle progression through G1. Yeast Tor2 has an additional role in regulating the integrity of the cell wall by activating the Rho1 guanine nucleotide exchange factor Rom2. The endocytic defect in tor2G2128Rcells is due to disruption of this Tor2 unique function. Other proteins important for cell integrity, Rom2 and the cell integrity sensor Wsc1, are also required for efficient endocytosis. A rho1 mutant specifically defective in activation of the glucan synthase Fks1/2 does not internalize α-factor efficiently, and fks1Δ cells exhibit a similar phenotype. Removal of the cell wall does not inhibit internalization, suggesting that the function of Rho1 and Fks1 in endocytosis is not through cell wall synthesis or structural integrity. These findings reveal a novel function for the Tor2-Rho1 pathway in controlling endocytosis in yeast, a function that is mediated in part through the plasma membrane protein Fks1.

scholarly journals The Role of Arabinogalactan Type II Degradation in Plant-Microbe Interactions

2021 ◽  
Vol 12 ◽  
Author(s):  
Maria Guadalupe Villa-Rivera ◽  
Horacio Cano-Camacho ◽  
Everardo López-Romero ◽  
María Guadalupe Zavala-Páramo
Keyword(s):  
Cell Wall ◽  
Plant Defense ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Degradation Products ◽  
Hydrolytic Enzymes ◽  
Pathogenic Fungi ◽  
Plant Interactions ◽  
Root Tips ◽  
Microbe Interactions

Arabinogalactans (AGs) are structural polysaccharides of the plant cell wall. A small proportion of the AGs are associated with hemicellulose and pectin. Furthermore, AGs are associated with proteins forming the so-called arabinogalactan proteins (AGPs), which can be found in the plant cell wall or attached through a glycosylphosphatidylinositol (GPI) anchor to the plasma membrane. AGPs are a family of highly glycosylated proteins grouped with cell wall proteins rich in hydroxyproline. These glycoproteins have important and diverse functions in plants, such as growth, cellular differentiation, signaling, and microbe-plant interactions, and several reports suggest that carbohydrate components are crucial for AGP functions. In beneficial plant-microbe interactions, AGPs attract symbiotic species of fungi or bacteria, promote the development of infectious structures and the colonization of root tips, and furthermore, these interactions can activate plant defense mechanisms. On the other hand, plants secrete and accumulate AGPs at infection sites, creating cross-links with pectin. As part of the plant cell wall degradation machinery, beneficial and pathogenic fungi and bacteria can produce the enzymes necessary for the complete depolymerization of AGs including endo-β-(1,3), β-(1,4) and β-(1,6)-galactanases, β-(1,3/1,6) galactanases, α-L-arabinofuranosidases, β-L-arabinopyranosidases, and β-D-glucuronidases. These hydrolytic enzymes are secreted during plant-pathogen interactions and could have implications for the function of AGPs. It has been proposed that AGPs could prevent infection by pathogenic microorganisms because their degradation products generated by hydrolytic enzymes of pathogens function as damage-associated molecular patterns (DAMPs) eliciting the plant defense response. In this review, we describe the structure and function of AGs and AGPs as components of the plant cell wall. Additionally, we describe the set of enzymes secreted by microorganisms to degrade AGs from AGPs and its possible implication for plant-microbe interactions.

Growth and Division of the Peptidoglycan Matrix

2021 ◽  
Vol 75 (1) ◽  
Author(s):  
Patricia D.A. Rohs ◽  
Thomas G. Bernhardt
Keyword(s):  
Cell Wall ◽  
Bacterial Infections ◽  
Model Organisms ◽  
Annual Review ◽  
Publication Date ◽  
Drug Resistant ◽  
Peptidoglycan Cell Wall ◽  
Integral Role ◽  
Osmotic Lysis ◽  
Peptidoglycan Layer

Most bacteria are surrounded by a peptidoglycan cell wall that defines their shape and protects them from osmotic lysis. The expansion and division of this structure therefore plays an integral role in bacterial growth and division. Additionally, the biogenesis of the peptidoglycan layer is the target of many of our most effective antibiotics. Thus, a better understanding of how the cell wall is built will enable the development of new therapies to combat the rise of drug-resistant bacterial infections. This review covers recent advances in defining the mechanisms involved in assembling the peptidoglycan layer with an emphasis on discoveries related to the function and regulation of the cell elongation and division machineries in the model organisms Escherichia coli and Bacillus subtilis. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Sign in / Sign up

Export Citation Format

Share Document