Plant peptidoglycan precursor biosynthesis: Conservation between moss chloroplasts and Gram negative bacteria

An accumulation of evidence suggests that peptidoglycan, consistent with a bacterial cell wall, is synthesised around the chloroplasts of many photosynthetic eukaryotes, from glaucophyte algae to land plants at least as evolved as pteridophyte ferns, but the biosynthetic pathway has not been demonstrated. We employed mass spectrometry and enzymology in a two fold approach to characterize the synthesis of peptidoglycan in chloroplasts of the moss Physcomitrium (Physcomitrella) patens. To drive the accumulation of peptidoglycan pathway intermediates, P.patens was cultured with the antibiotics phosphomycin, D-cycloserine and carbenicillin, which inhibit key peptidoglycan pathway proteins in bacteria. Mass spectrometry of the TCA-extracted moss metabolome revealed elevated levels of five of the predicted intermediates from UDP-GlcNAc through to the UDP-MurNAc-D,L-diaminopimelate (DAP)-pentapeptide. Most Gram negative bacteria, including cyanobacteria, incorporate meso-diaminopimelate (D,L-DAP) into the third residue of the stem peptide of peptidoglycan, as opposed to L-Lysine, typical of most Gram positive bacteria. To establish the specificity of D,L-DAP incorporation into the P.patens precursors, we analysed the recombinant protein that appends the third stem peptide amino acid, UDP-MurNAc-tripeptide ligase (MurE), from both P.patens and the cyanobacterium Anabaena sp. strain PCC 7120. Both ligases incorporated D,L-DAP in almost complete preference to L-Lys, consistent with the mass spectrophotometric data, with catalytic efficiencies similar to previously documented Gram negative bacterial MurE ligases. We discuss how these data accord with the conservation of active site residues common to DL-DAP-incorporating bacterial MurE ligases and of the probability of a horizontal gene transfer event within the plant peptidoglycan pathway.

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Direct detection of lipid A on intact Gram-negative bacteria by MALDI-TOF mass spectrometry

Journal of Microbiological Methods ◽

10.1016/j.mimet.2015.12.004 ◽

2016 ◽

Vol 120 ◽

pp. 68-71 ◽

Cited By ~ 22

Author(s):

Gerald Larrouy-Maumus ◽

Abigail Clements ◽

Alain Filloux ◽

Ronan R. McCarthy ◽

Serge Mostowy

Keyword(s):

Mass Spectrometry ◽

Lipid A ◽

Direct Detection ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Maldi Tof Mass Spectrometry ◽

Maldi Tof

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Fusaricidins, Polymyxins and Volatiles Produced by Paenibacillus polymyxa Strains DSM 32871 and M1

10.20944/preprints202110.0268.v1 ◽

2021 ◽

Author(s):

Pascal Mülner ◽

Elisa Schwarz ◽

Kristin Dietel ◽

Stefanie Herfort ◽

Jennifer Jähne ◽

...

Keyword(s):

Mass Spectrometry ◽

Characteristic Feature ◽

Fungal Pathogens ◽

Paenibacillus Polymyxa ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Antifungal Activities ◽

Maldi Tof Mass Spectrometry ◽

Maldi Tof ◽

Volatile Organic

Paenibacilli are efficient producers of potent agents against bacterial and fungal pathogens, which are of great interest both for therapeutic applications in medicine as well as in agrobiotechnol-ogy. Lipopeptides produced by such organisms play a major role in their inactivation potential. In this work we investigated two lipopeptide complexes, the fusaricidins and the polymyxins, produced by Paenibacillus polymyxa strains DSM 32871 and M1 by MALDI-TOF mass spectrometry. The fusaricidins show potent antifungal activities and are distinguished by an unusual variabil-ity. For strain DSM 32871 we identified numerous yet unknown variants mass spectrometrically. DSM 32871 produces polymyxins of type E (colistins), while M1 forms polymyxins P. For both strains novel, but not yet completely characterized polymyxin species were detected, which pos-sibly are glycosylated. These compounds may be of interest therapeutically, because polymyxins attain increasing attention as last-resort antibiotics against multiresistant pathogenic Gram-negative bacteria. In addition, the volatilomes of DSM 32781 and M1 were investigated with a GC-MS approach using different cultivation media. Production of volatile organic com-pounds (VOCs) was strain and medium dependent. In particular, strain M1 manifested as an effi-cient VOC-producer that exhibited formation of 25 volatiles in total. A characteristic feature of Paenibacilli is the formation of volatile pyrazine derivatives.

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Synthesis of Some New Nucleoside Analogues Containing Seven Membered Ring and Studying Their Biological Activity

Baghdad Science Journal ◽

10.21123/bsj.13.3.531-546 ◽

2016 ◽

Vol 13 (3) ◽

pp. 531-546

Author(s):

Baghdad Science Journal

Keyword(s):

Antibacterial Activity ◽

Membered Ring ◽

Nucleoside Analogues ◽

Second Step ◽

Gram Negative Bacteria ◽

Gram Negative ◽

The Third ◽

Ft Ir ◽

Fourth Step ◽

Propiolic Acid

In this work, a series of new Nucleoside analogues (D-galactopyranose linked to oxepanebenzimidazole moiety) was synthesized via multisteps synthesis. The first step involved preparation of two benzimidazoles 2-styrylbenzimidazole and 2-(phenyl ethynyl) benzimidazole via reaction of phenylenediamine with cinnamic acid or ?-phenyl propiolic acid. Electrophilic addition of the prepared benzimidazoles by three anhydrides in the second step afforded (4-6) and (14-16) which in turn were treated with 1,2,3,4-di-O-isopropylidene galactopyranose in the third step to afford a series of the desirable protected nucleoside analogues (7-9) ,(17-19)which after hydrolysis in methanolic sodium methoxidein the fourth step afforded the free nucleoside analogues (10-12) and (20-22) .The synthesized compounds were identified by FT-IR and some of them by 1H-NMR and13C-NMR. The synthesized oxepane nucleoside analogues were screened for their antibacterial activity against three types of bacteria including Staphylococcusaureus ,Bacillus(gram positive) andE.coli (gram negative) bacteria repectively.

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Fusobacterium nucleatum, the first Gram-negative bacterium demonstrated to produce polyglutamate

Canadian Journal of Microbiology ◽

10.1139/w09-003 ◽

2009 ◽

Vol 55 (5) ◽

pp. 627-632 ◽

Cited By ~ 33

Author(s):

Thomas Candela ◽

Marie Moya ◽

Michel Haustant ◽

Agnès Fouet

Keyword(s):

In Silico Analysis ◽

Fusobacterium Nucleatum ◽

Gram Negative Bacteria ◽

Negative Bacterium ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

The Third ◽

Gram Negative Organisms ◽

First Time

Poly-γ-glutamate has been described in many Gram-positive organisms. When anchored to the surface, it is a capsule and as such a virulence factor. Based on sequence similarities, few Gram-negative organisms have been suggested to synthesize poly-γ-glutamate. For the first time, a Gram-negative bacterium, Fusobacterium nucleatum , is shown to produce and secrete poly-γ-glutamate. Putative poly-γ-glutamate-synthesizing genes from Gram-negative organisms have been compared with their Gram-positive homologs by in silico analysis, i.e., gene sequence and phylogenetic analysis. Clusters of three instead of four genes were highlighted by our screen. The products of the first two genes display similarity with their Gram-positive equivalents, yet the sequences from the Gram-negative organisms can be distinguished from those of the Gram-positives. Interestingly, the sequence of the predicted product of the third gene is conserved among Gram-negative bacteria but displays no similarity to that of either the third or fourth gene of the Gram-positive operons. It is suggested that, like for Gram-positive bacteria, poly-γ-glutamate has a role in virulence for pathogens and one in survival for other Gram-negative bacteria.

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Discrimination of Some Gram-negative Bacteria by Direct Probe Mass Spectrometry

Microbiology ◽

10.1099/00221287-128-4-721 ◽

1982 ◽

Vol 128 (4) ◽

pp. 721-730

Author(s):

C. S. Gutteridge ◽

D. J. Puckey

Keyword(s):

Mass Spectrometry ◽

Gram Negative Bacteria ◽

Gram Negative

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Glycosides from Cephalaria Species

Zeitschrift für Naturforschung B ◽

10.1515/znb-2010-1115 ◽

2010 ◽

Vol 65 (11) ◽

pp. 1384-1392 ◽

Cited By ~ 4

Author(s):

Erkan Halay ◽

Süheyla Kırmızıgül

Keyword(s):

Mass Spectrometry ◽

Oleanolic Acid ◽

2D Nmr ◽

Spectroscopic Methods ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Nmr Techniques ◽

Basic Hydrolysis ◽

Hydrolysis Of ◽

Chemical Evidence

Three novel triterpene glycosides (1 - 3), namely lycicoside I, II and cilicicoside I, were isolated from two different Cephalaria (Dipsacaceae) species along with one known oleanane- and one iridoit- type of glycoside. The structures of these compounds were established as 3-O-[β -D-glucopyranosyl( 1→3)-α-L-rhamnopyranosyl(1→4)-β -D-xylopyranosyl(1→4)-β -D-xylopyranosyl]-28-O-[β -Dglucopyranosyl( 1→6)-β -D-glucopyranosyl]-oleanolic acid (1), 3-O-[β -D-xylopyranosyl(1→3)-α- L-rhamnopyranosyl(1→4)-β -D-xylopyranosyl]-28-O-[β -D-glucopyranosyl]-oleanolic acid (2) from Cephalaria lycica Matthew and 3-O-{β -D-glucopyranosyl(1→4)-β -D-xylopyranosyl(1→3)-α-Lrhamnopyranosyl( 1→2)-[β -D-glucopyranosyl(1→3)]-α -L-rhamnopyranosyl}-28-O-[β -D-glucopyranosyl( 1→6)-β -D-glucopyranosyl]-hederagenin (3) from Cephalaria cilicica Boiss. & Kotschy, on the basis of spectroscopic methods (1D and 2D NMR techniques, mass spectrometry) and chemical evidence. In addition, three new prosapogenins, 1B - 3B, were obtained from the basic hydrolysis of 1 - 3. The antimicrobial activity of 1 - 3 was tested against some Gram-positive and Gram-negative bacteria strains.

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