scholarly journals Characterization of the Depletion of 2-C-Methyl-d-Erythritol-2,4-Cyclodiphosphate Synthase in Escherichia coli and Bacillus subtilis

2002 ◽  
Vol 184 (20) ◽  
pp. 5609-5618 ◽  
Author(s):  
Tracey L. Campbell ◽  
Eric D. Brown
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Bacillus Subtilis ◽  
Gene Product ◽  
Cell Walls ◽  
Isoprenoid Biosynthesis ◽  
Synthetic Lethal ◽  
E Coli

ABSTRACT The ispF gene product in Escherichia coli has been shown to catalyze the formation of 2-C-methyl-d-erythritol 2,4-cyclodiphosphate (MEC) in the deoxyxylulose (DOXP) pathway for isoprenoid biosynthesis. In this work, the E. coli gene ispF and its Bacillus subtilis orthologue, yacN, were deleted and conditionally complemented by expression of these genes from distant loci in the respective organisms. In E. coli, complementation was achieved through integration of ispF at the araBAD locus with control from the arabinose-inducible araBAD promoter, while in B. subtilis, yacN was placed at amyE under control of the xylose-inducible xylA promoter. In both cases, growth was severely retarded in the absence of inducer, consistent with these genes being essential for survival. E. coli cells depleted of MEC synthase revealed a filamentous phenotype. This was in contrast to the depletion of MEC synthase in B. subtilis, which resulted in a loss of rod shape, irregular septation, multicompartmentalized cells, and thickened cell walls. To probe the nature of the predominant deficiency of MEC synthase-depleted cells, we investigated the sensitivity of these conditionally complemented mutants, grown with various concentrations of inducer, to a wide variety antibiotics. Synthetic lethal behavior in MEC synthase-depleted cells was prevalent for cell wall-active antibiotics.

scholarly journals Regeneration of Escherichia coli Giant Protoplasts to Their Original Form

Life ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 24 ◽  
Author(s):  
Kazuhito V. Tabata ◽  
Takao Sogo ◽  
Yoshiki Moriizumi ◽  
Hiroyuki Noji
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Bacillus Subtilis ◽  
Colony Formation ◽  
Cell Walls ◽  
Microscopic Investigation ◽  
Original Form ◽  
Cell Wall Synthesis ◽  
E Coli ◽  
The Relationship

The spheroplasts and protoplasts of cell wall-deficient (CWD) bacteria are able to revert to their original cellular morphologies through the regeneration of their cell walls. However, whether this is true for giant protoplasts (GPs), which can be as large as 10 μm in diameter, is unknown. GPs can be prepared from various bacteria, including Escherichia coli and Bacillus subtilis, and also from fungi, through culture in the presence of inhibitors for cell wall synthesis or mitosis. In this report, we prepared GPs from E. coli and showed that they can return to rod-shaped bacterium, and that they are capable of colony formation. Microscopic investigation revealed that the regeneration process took place through a variety of morphological pathways. We also report the relationship between GP division and GP volume. Finally, we show that FtsZ is crucial for GP division. These results indicate that E. coli is a highly robust organism that can regenerate its original form from an irregular state, such as GP.

scholarly journals Identification and Characterization of Genes Required for 5-Hydroxyuridine Synthesis in Bacillus subtilis and Escherichia coli tRNA

2019 ◽  
Vol 201 (20) ◽  
Author(s):  
Charles T. Lauhon
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Genomic Context ◽  
Similar Reduction ◽  
Content Type ◽  
E Coli ◽  
Wobble Position ◽  
Fertile Ground ◽  
And Function

ABSTRACT In bacteria, tRNAs that decode 4-fold degenerate family codons and have uridine at position 34 of the anticodon are typically modified with either 5-methoxyuridine (mo5U) or 5-methoxycarbonylmethoxyuridine (mcmo5U). These modifications are critical for extended recognition of some codons at the wobble position. Whereas the alkylation steps of these modifications have been described, genes required for the hydroxylation of U34 to give 5-hydroxyuridine (ho5U) remain unknown. Here, a number of genes in Escherichia coli and Bacillus subtilis are identified that are required for wild-type (wt) levels of ho5U. The yrrMNO operon is identified in B. subtilis as important for the biosynthesis of ho5U. Both yrrN and yrrO are homologs to peptidase U32 family genes, which includes the rlhA gene required for ho5C synthesis in E. coli. Deletion of either yrrN or yrrO, or both, gives a 50% reduction in mo5U tRNA levels. In E. coli, yegQ was found to be the only one of four peptidase U32 genes involved in ho5U synthesis. Interestingly, this mutant shows the same 50% reduction in (m)cmo5U as that observed for mo5U in the B. subtilis mutants. By analyzing the genomic context of yegQ homologs, the ferredoxin YfhL is shown to be required for ho5U synthesis in E. coli to the same extent as yegQ. Additional genes required for Fe-S biosynthesis and biosynthesis of prephenate give the same 50% reduction in modification. Together, these data suggest that ho5U biosynthesis in bacteria is similar to that of ho5C, but additional genes and substrates are required for complete modification. IMPORTANCE Modified nucleotides in tRNA serve to optimize both its structure and function for accurate translation of the genetic code. The biosynthesis of these modifications has been fertile ground for uncovering unique biochemistry and metabolism in cells. In this work, genes that are required for a novel anaerobic hydroxylation of uridine at the wobble position of some tRNAs are identified in both Bacillus subtilis and Escherichia coli. These genes code for Fe-S cluster proteins, and their deletion reduces the levels of the hydroxyuridine by 50% in both organisms. Additional genes required for Fe-S cluster and prephenate biosynthesis and a previously described ferredoxin gene all display a similar reduction in hydroxyuridine levels, suggesting that still other genes are required for the modification.

Analysis of the Crushing Effect about Ultrasound on E. coli and B. subtilis

2012 ◽  
Vol 260-261 ◽  
pp. 1017-1021
Author(s):  
Xin Ying Wang ◽  
Yong Tao Liu ◽  
Min Hui ◽  
Ji Fei Xu
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Bacillus Subtilis ◽  
Bacterial Cell ◽  
Logarithmic Phase ◽  
Growth Stages ◽  
Bacterial Cells ◽  
E Coli ◽  
Different Growth Stages ◽  
Main Factor

Escherichia coli and Bacillus subtilis as objects of the study, ultrasonic fragmentation acted on the bacterial cells in different growth stages, results showed that, it’s similar to the crushing effect of ultrasound on E. coli and B. subtilis cells of different growth stages, the highest crushing rate in the logarithmic phase, reached to 95.8% and 94.3% respectively, the crushing rate of adjustment phase is lowest, maintained at around 60%, the crushing rate stability cell was centered, which can be achieved 90%. The structure of the bacterial cell wall didn’t the main factor to decide the ultrasonic fragmentation effect, but different growth periods of bacterial cells did the determinant.

scholarly journals MurJ and a novel lipid II flippase are required for cell wall biogenesis in Bacillus subtilis

2015 ◽  
Vol 112 (20) ◽  
pp. 6437-6442 ◽  
Author(s):  
Alexander J. Meeske ◽  
Lok-To Sham ◽  
Harvey Kimsey ◽  
Byoung-Mo Koo ◽  
Carol A. Gross ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis ◽  
Cell Envelope ◽  
Synthetic Lethal ◽  
Bacterial Surface ◽  
E Coli ◽  
Lipid Ii ◽  
Cell Wall Biogenesis ◽  
Morphological Defects ◽  
Surface Polysaccharides

Bacterial surface polysaccharides are synthesized from lipid-linked precursors at the inner surface of the cytoplasmic membrane before being translocated across the bilayer for envelope assembly. Transport of the cell wall precursor lipid II in Escherichia coli requires the broadly conserved and essential multidrug/oligosaccharidyl-lipid/polysaccharide (MOP) exporter superfamily member MurJ. Here, we show that Bacillus subtilis cells lacking all 10 MOP superfamily members are viable with only minor morphological defects, arguing for the existence of an alternate lipid II flippase. To identify this factor, we screened for synthetic lethal partners of MOP family members using transposon sequencing. We discovered that an uncharacterized gene amj (alternate to MurJ; ydaH) and B. subtilis MurJ (murJBs; formerly ytgP) are a synthetic lethal pair. Cells defective for both Amj and MurJBs exhibit cell shape defects and lyse. Furthermore, expression of Amj or MurJBs in E. coli supports lipid II flipping and viability in the absence of E. coli MurJ. Amj is present in a subset of gram-negative and gram-positive bacteria and is the founding member of a novel family of flippases. Finally, we show that Amj is expressed under the control of the cell envelope stress-response transcription factor σM and cells lacking MurJBs increase amj transcription. These findings raise the possibility that antagonists of the canonical MurJ flippase trigger expression of an alternate translocase that can resist inhibition.

scholarly journals THE NATURE OF THE COLICIN K RECEPTOR OF ESCHERICHIA COLI CULLEN

1971 ◽  
Vol 133 (3) ◽  
pp. 534-553 ◽  
Author(s):  
Hans Ulrich Weltzien ◽  
Margeris A. Jesaitis
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Biological Activity ◽  
Amino Acid ◽  
Cell Walls ◽  
Cytoplasmic Membrane ◽  
Proteolytic Enzymes ◽  
E Coli ◽  
Chemical Reagents ◽  
Specific Receptors

Cell walls of E. coli strains B and Cullen contain specific receptors for colicin K and for the T2, T6, and C16 phages. The receptors for the bacteriocin and the T6 virus are located in the outer layers of the cell wall of these microorganisms and are absent in their cytoplasmic membrane. The receptors for colicin K, phage T2, and the T6 and C16 viruses differ in their stability toward enzymes and chemical reagents. Their specificity must therefore be determined by different chemical groupings. The colicin K receptor is inactivated by certain proteolytic enzymes and by reagents which combine with tryptophan. It is concluded therefore that proteins or peptides containing this amino acid are essential for biological activity of the receptor.

scholarly journals Characterization of YvcJ, a Conserved P-Loop-Containing Protein, and Its Implication in Competence in Bacillus subtilis

2008 ◽  
Vol 191 (5) ◽  
pp. 1556-1564 ◽  
Author(s):  
Jennifer Luciano ◽  
Elodie Foulquier ◽  
Jean-Raphael Fantino ◽  
Anne Galinier ◽  
Frédérique Pompeo
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Transformation Efficiency ◽  
Cellular Function ◽  
Protein Family ◽  
Wild Type ◽  
Uncharacterized Protein ◽  
E Coli ◽  
Phosphate Synthase

ABSTRACT The uncharacterized protein family UPF0042 of the Swiss-Prot database is predicted to be a member of the conserved group of bacterium-specific P-loop-containing proteins. Here we show that two of its members, YvcJ from Bacillus subtilis and YhbJ, its homologue from Escherichia coli, indeed bind and hydrolyze nucleotides. The cellular function of yvcJ was then addressed. In contrast to results recently obtained for E. coli, which indicated that yhbJ mutants strongly overproduced glucosamine-6-phosphate synthase (GlmS), comparison of the wild type with the yvcJ mutant of B. subtilis showed that GlmS expression was quite similar in the two strains. However, in mutants defective in yvcJ, the transformation efficiency and the fraction of cells that expressed competence were reduced. Furthermore, our data show that YvcJ positively controls the expression of late competence genes. The overexpression of comK or comS compensates for the decrease in competence of the yvcJ mutant. Our results show that even if YvcJ and YhbJ belong to the same family of P-loop-containing proteins, the deletion of corresponding genes has different consequences in B. subtilis and in E. coli.

scholarly journals Detection of ipaH gene in Large Plasmid of Escherichia coli Isolated from Different Sources of Bangladesh

2012 ◽  
Vol 28 (2) ◽  
pp. 84-87
Author(s):  
Fahmina Akhter ◽  
M Fakruddin ◽  
Nafisa Azmuda ◽  
Anowara Begum ◽  
Nils Kare Birkeland ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gene Product ◽  
Plasmid Dna ◽  
Large Plasmid ◽  
Chromosomal Dna ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Large Plasmids ◽  
Different Sources

Large plasmid (more than 100 MDa) plays a significant role in Escherichia coli virulence as many virulent genes including the ipaH are encoded by large plasmids. Characterization of such large plasmid of E. coli from different sources based on ipaH gene has not yet been reported with success and credible reproducibility in Bangladesh. Forty E. coli isolates of environmental, clinical, avian, and mammalian sources were examined to detect the presence of large plasmids. Among them, plasmids recovered from 32 isolates were found to range between 100 and 145 MDa in size. Antibiotic susceptibility pattern of the isolates against 17 different  antibiotics showed that most of them were resistant to more than 6 antibiotics and thus were designated multiple antibiotic resistant (MAR) strains. Out of 32 isolates, 10 were (3 clinical, 5 environmental, 1 avian and 1 mammalian source) found to possess a gene product of 423 bp size after PCR assay from plasmid DNA. Southern hybridization was carried out with ipaH probes and the results revealed the presence of band of correct size in both large plasmid DNA and in chromosomal DNA. Presence of the appropriate gene product in newly discharged environmental E. coli strains questions the credibility of using these bacteria as an indicator of water pollution in tropical countries like Bangladesh. The innovative approaches employed in this investigation regarding characterization of large plasmid based on the presence of ipaH gene in E. coli isolates from environmental, clinical, avian and mammalian sources opened up avenues for challenging research in future. DOI: http://dx.doi.org/10.3329/bjm.v28i2.11822 Bangladesh J Microbiol, Volume 28, Number 2, December 2011, pp 84-87

Sites of Adsorption of the Bacteriophages T3 and T5 on the Wall of Escherichia Coli B.

1967 ◽  
Vol 25 ◽  
pp. 96-97
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Electron Microscope ◽  
Uranyl Acetate ◽  
E Coli ◽  
Receptor Sites ◽  
Rigid Cell Wall ◽  
Host Cell Surface ◽  
Bacterial Viruses ◽  
Escherichia Coli B

Bacterial viruses adsorb specifically to receptors on the host cell surface. Although the chemical composition of some of the cell wall receptors for bacteriophages of the T-series has been described and the number of receptor sites has been estimated to be 150 to 300 per E. coli cell, the localization of the sites on the bacterial wall has been unknown.When logarithmically growing cells of E. coli are transferred into a medium containing 20% sucrose, the cells plasmolize: the protoplast shrinks and becomes separated from the somewhat rigid cell wall. When these cells are fixed in 8% Formaldehyde, post-fixed in OsO4/uranyl acetate, embedded in Vestopal W, then cut in an ultramicrotome and observed with the electron microscope, the separation of protoplast and wall becomes clearly visible, (Fig. 1, 2). At a number of locations however, the protoplasmic membrane adheres to the wall even under the considerable pull of the shrinking protoplast. Thus numerous connecting bridges are maintained between protoplast and cell wall. Estimations of the total number of such wall/membrane associations yield a number of about 300 per cell.

Antagonistic activity of Bacillus subtilis strains isolated from various sources

2018 ◽  
Vol 8 (2) ◽  
pp. 354-364
Author(s):  
A. N. Irkitova ◽  
A. V. Grebenshchikova ◽  
A. V. Matsyura
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Wild Strain ◽  
Fish Farming ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
E Coli ◽  
Long Period ◽  
Test Culture ◽  
Agar Media

<p>An important link in solving the problem of healthy food is the intensification of the livestock, poultry and fish farming, which is possible only in the adoption and rigorous implementation of the concept of rational feeding of animals. In the implementation of this concept required is the application of probiotic preparations. Currently, there is an increased interest in spore probiotics. In many ways, this can be explained by the fact that they use no vegetative forms of the bacilli and their spores. This property provides spore probiotics a number of advantages: they are not whimsical, easily could be selected, cultivated, and dried. Moreover, they are resistant to various factors and could remain viable during a long period. One of the most famous spore microorganisms, which are widely used in agriculture, is <em>Bacillus subtilis</em>. Among the requirements imposed to probiotic microorganisms is mandatory – antagonistic activity to pathogenic and conditional-pathogenic microflora. The article presents the results of the analysis of antagonistic activity of collection strains of <em>B. subtilis</em>, and strains isolated from commercial preparations. We studied the antagonistic activity on agar and liquid nutrient medias to trigger different antagonism mechanisms of <em>B. subtilis</em>. On agar media, we applied three diffusion methods: perpendicular bands, agar blocks, agar wells. We also applied the method of co-incubating the test culture (<em>Escherichia coli</em>) and the antagonist (or its supernatant) in the nutrient broth. Our results demonstrated that all our explored strains of <em>B. subtilis</em> have antimicrobial activity against a wild strain of <em>E. coli</em>, but to varying degrees. We identified strains of <em>B. subtilis</em> with the highest antagonistic effect that can be recommended for inclusion in microbial preparations for agriculture.</p><p><em><br /></em><em></em></p>

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