scholarly journals Non-random segregation of sister chromosomes by Escherichia coli MukBEF axial cores

2020 ◽  
Author(s):  
Jarno Mäkelä ◽  
Stephan Uphoff ◽  
David J. Sherratt
Keyword(s):  
Escherichia Coli ◽  
Genetic Material ◽  
Temporal Organization ◽  
Translational Symmetry ◽  
Cell Axis ◽  
Chromosome Conformation ◽  
Random Segregation ◽  
Spatio Temporal ◽  
Replication Terminus ◽  
Dna Strand

SummaryThe Escherichia coli structural maintenance of chromosomes complex, MukBEF, forms axial cores to chromosomes that determine their spatio-temporal organization. Here, we show that axial cores direct chromosome arms to opposite poles and generate the translational symmetry between newly replicated sister chromosomes. MatP, a replication terminus (ter) binding protein prevents chromosome rotation around the longitudinal cell axis by displacing MukBEF from ter, thereby maintaining the linear shape of axial cores. During DNA replication, MukBEF action directs lagging strands towards the cell center, marked by accumulation of DNA-bound β2-clamps in the wake of replisomes, in a process necessary for the translational symmetry of sister chromosomes. Finally, the ancestral (‘immortal’) template DNA strand, propagated from previous generations, is preferentially inherited by the cell forming at the old pole, dependent on MukBEF-MatP. The work demonstrates how chromosome organization-segregation can foster non-random inheritance of genetic material and provides a framework for understanding how chromosome conformation and dynamics shape subcellular organization.

scholarly journals Nonrandom segregation of sister chromosomes by Escherichia coli MukBEF

2021 ◽  
Vol 118 (33) ◽  
pp. e2022078118
Author(s):  
Jarno Mäkelä ◽  
Stephan Uphoff ◽  
David J. Sherratt
Keyword(s):  
Escherichia Coli ◽  
Genetic Material ◽  
Chromosome Organization ◽  
Translational Symmetry ◽  
Chromosome Conformation ◽  
Domains Of Life ◽  
Replication Terminus ◽  
Dna Strand ◽  
Template Dna ◽  
Structural Maintenance Of Chromosomes

Structural maintenance of chromosomes (SMC) complexes contribute to chromosome organization in all domains of life. In Escherichia coli, MukBEF, the functional SMC homolog, promotes spatiotemporal chromosome organization and faithful chromosome segregation. Here, we address the relative contributions of MukBEF and the replication terminus (ter) binding protein, MatP, to chromosome organization–segregation. We show that MukBEF, but not MatP, is required for the normal localization of the origin of replication to midcell and for the establishment of translational symmetry between newly replicated sister chromosomes. Overall, chromosome orientation is normally maintained through division from one generation to the next. Analysis of loci flanking the replication termination region (ter), which demark the ends of the linearly organized portion of the nucleoid, demonstrates that MatP is required for maintenance of chromosome orientation. We show that DNA-bound β2-processivity clamps, which mark the lagging strands at DNA replication forks, localize to the cell center, independent of replisome location but dependent on MukBEF action, and consistent with translational symmetry of sister chromosomes. Finally, we directly show that the older (“immortal”) template DNA strand, propagated from previous generations, is preferentially inherited by the cell forming at the old pole, dependent on MukBEF and MatP. The work further implicates MukBEF and MatP as central players in chromosome organization, segregation, and nonrandom inheritance of genetic material and suggests a general framework for understanding how chromosome conformation and dynamics shape subcellular organization.

scholarly journals Antimicrobial activity of Syzygium aromaticum L. essential oil on extended-spectrum beta-lactamases-producing Escherichia coli

2020 ◽  
Vol 44 (1) ◽  
Author(s):  
E. L. Mejía-Argueta ◽  
J. G. Santillán-Benítez ◽  
M. M. Canales-Martinez ◽  
A. Mendoza-Medellín
Keyword(s):  
Escherichia Coli ◽  
Essential Oil ◽  
Genetic Material ◽  
Gastrointestinal Diseases ◽  
Syzygium Aromaticum ◽  
Antibiotic Resistant ◽  
Plant Essential Oils ◽  
E Coli ◽  
Extended Spectrum ◽  
Tract Infections

Abstract Background To test the antimicrobial potential of clove essential oil that has been less investigated on antimicrobial-resistant organisms (extended-spectrum β-lactamase-ESBL-producing Escherichia coli), we collected 135 ESBL-producing Escherichia coli strains given that E. coli is the major organism increasingly isolated as a cause of complicated urinary and gastrointestinal tract infections, which remains an important cause of therapy failure with antibiotics for the medical sector. Then, in this study, we evaluated the relationship between the antibacterial potential activity of Syzygium aromaticum essential oil (EOSA) and the expression of antibiotic-resistant genes (SHV-2, TEM-20) in plasmidic DNA on ESBL-producing E. coli using RT-PCR technique. Results EOSA was obtained by hydrodistillation. Using Kirby-Baüer method, we found that EOSA presented a smaller media (mean = 15.59 mm) in comparison with chloramphenicol (mean = 17.73 mm). Thus, there were significant differences (p < 0.0001). Furthermore, EOSA had an antibacterial activity, particularly on ECB132 (MIC: 10.0 mg/mL and MBC: 80.0 mg/mL), and a bacteriostatic effect by bactericidal kinetic. We found that the expression of antibiotic-resistant gene blaTEM-20 was 23.52% (4/17 strains) and no expression of blaSHV-2. EOSA presented such as majority compounds (eugenol, caryophyllene) using the GC–MS technique. Conclusions Plant essential oils and their active ingredients have potentially high bioactivity against a different target (membranes, cytoplasm, genetic material). In this research, EOSA might become an important adjuvant against urinary and gastrointestinal diseases caused by ESBL-producing E. coli.

scholarly journals The spatio-temporal organization of mitochondrial F1FO ATP synthase in cristae depends on its activity mode

2020 ◽  
Vol 1861 (1) ◽  
pp. 148091 ◽  
Author(s):  
Kirill Salewskij ◽  
Bettina Rieger ◽  
Frances Hager ◽  
Tasnim Arroum ◽  
Patrick Duwe ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Temporal Organization ◽  
F1fo Atp Synthase ◽  
Activity Mode ◽  
Spatio Temporal

scholarly journals A Pathoadaptive Deletion in an Enteroaggregative Escherichia coli Outbreak Strain Enhances Virulence in a Caenorhabditis elegans Model

2010 ◽  
Vol 78 (9) ◽  
pp. 4068-4076 ◽  
Author(s):  
Jennifer Hwang ◽  
Lisa M. Mattei ◽  
Laura G. VanArendonk ◽  
Philip M. Meneely ◽  
Iruka N. Okeke
Keyword(s):  
Escherichia Coli ◽  
Caenorhabditis Elegans ◽  
Epithelial Cells ◽  
Genetic Material ◽  
Decarboxylase Activity ◽  
Multicopy Plasmid ◽  
Lysine Decarboxylase ◽  
Outbreak Strain ◽  
E Coli ◽  
C Elegans

ABSTRACT Enteroaggregative Escherichia coli (EAEC) strains are important diarrheal pathogens. EAEC strains are defined by their characteristic stacked-brick pattern of adherence to epithelial cells but show heterogeneous virulence and have different combinations of adhesin and toxin genes. Pathoadaptive deletions in the lysine decarboxylase (cad) genes have been noted among hypervirulent E. coli subtypes of Shigella and enterohemorrhagic E. coli. To test the hypothesis that cad deletions might account for heterogeneity in EAEC virulence, we developed a Caenorhabditis elegans pathogenesis model. Well-characterized EAEC strains were shown to colonize and kill C. elegans, and differences in virulence could be measured quantitatively. Of 49 EAEC strains screened for lysine decarboxylase activity, 3 tested negative. Most notable is isolate 101-1, which was recovered in Japan, from the largest documented EAEC outbreak. EAEC strain 101-1 was unable to decarboxylate lysine in vitro due to deletions in cadA and cadC, which, respectively, encode lysine decarboxylase and a transcriptional activator of the cadAB genes. Strain 101-1 was significantly more lethal to C. elegans than control strain OP50. Lethality was attenuated when the lysine decarboxylase defect was complemented from a multicopy plasmid and in single copy. In addition, restoring lysine decarboxylase function produced derivatives of 101-1 deficient in aggregative adherence to cultured human epithelial cells. Lysine decarboxylase inactivation is pathoadapative in an important EAEC outbreak strain, and deletion of cad genes could produce hypervirulent EAEC lineages in the future. These results suggest that loss, as well as gain, of genetic material can account for heterogeneous virulence among EAEC strains.

scholarly journals Characterization of Escherichia coli DNA Lesions Generated within J774 Macrophages

2000 ◽  
Vol 182 (18) ◽  
pp. 5225-5230 ◽  
Author(s):  
Eliana Schlosser-Silverman ◽  
Maya Elgrably-Weiss ◽  
Ilan Rosenshine ◽  
Ron Kohen ◽  
Shoshy Altuvia
Keyword(s):  
Escherichia Coli ◽  
Dna Damage ◽  
Respiratory Burst ◽  
Defense Mechanism ◽  
Dna Lesions ◽  
Intracellular Bacteria ◽  
Bacterial Killing ◽  
Strand Breaks ◽  
E Coli ◽  
Dna Strand

ABSTRACT Macrophages are armed with multiple oxygen-dependent and -independent bactericidal properties. However, the respiratory burst, generating reactive oxygen species, is believed to be a major cause of bacterial killing. We exploited the susceptibility of Escherichia coli in macrophages to characterize the effects of the respiratory burst on intracellular bacteria. We show that E. coli strains recovered from J774 macrophages exhibit high rates of mutations. We report that the DNA damage generated inside macrophages includes DNA strand breaks and the modification 8-oxo-2′-deoxyguanosine, which are typical oxidative lesions. Interestingly, we found that under these conditions, early in the infection the majority of E. coli cells are viable but gene expression is inhibited. Our findings demonstrate that macrophages can cause severe DNA damage to intracellular bacteria. Our results also suggest that protection against the macrophage-induced DNA damage is an important component of the bacterial defense mechanism within macrophages.

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