Efficient utilization of ectoine by halophilic Brevibacterium species and Escherichia coli subjected to osmotic downshock

2005 ◽  
Vol 99 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Shinichi Nagata ◽  
Chenxiang Wang
Keyword(s):  
Escherichia Coli ◽  
Efficient Utilization ◽  
Osmotic Downshock

scholarly journals Engineering of Escherichia coli to facilitate efficient utilization of isomaltose and panose in industrial glucose feedstock

2016 ◽  
Vol 101 (5) ◽  
pp. 2057-2066 ◽  
Author(s):  
Kenji Abe ◽  
Akio Kuroda ◽  
Ryo Takeshita
Keyword(s):  
Escherichia Coli ◽  
Efficient Utilization

scholarly journals Coordinated Replication and Sequestration of oriC and dnaA Are Required for Maintaining Controlled Once-per-Cell-Cycle Initiation in Escherichia coli

2005 ◽  
Vol 187 (16) ◽  
pp. 5605-5613 ◽  
Author(s):  
Leise Riber ◽  
Anders Løbner-Olesen
Keyword(s):  
Escherichia Coli ◽  
Cell Cycle ◽  
Protein Concentration ◽  
Gene Promoter ◽  
Wild Type ◽  
Significant Delay ◽  
Efficient Utilization ◽  
Circular Chromosome ◽  
Normal Length ◽  
Dnaa Protein

ABSTRACT Escherichia coli cells were constructed in which the dnaA gene was moved to a location opposite oriC on the circular chromosome. In these cells the dnaA gene was replicated with significant delay relative to the origin. Consequently, the period where the newly replicated and hemimethylated oriC was sequestered no longer coincided with the period where the dnaA gene promoter was sequestered. DnaA protein synthesis was therefore expected to continue during origin sequestration. Despite a normal length of the sequestration period in such cells, they had increased origin content and also displayed asynchrony of initiation. This indicated that reinitiation occasionally occurred at some origins within the same cell cycle. The extra initiations took place in spite of a reduction in total DnaA protein concentration to about half of the wild-type level. We propose that this more efficient utilization of DnaA protein results from an increased availability at the end of the origin sequestration period. Therefore, coordinated sequestration of oriC and dnaA is required for maintaining controlled once-per-cell-cycle initiation.

scholarly journals A Single Mechanosensitive Channel ProtectsFrancisella tularensissubsp.holarcticafrom Hypoosmotic Shock and Promotes Survival in the Aquatic Environment

2017 ◽  
Vol 84 (5) ◽  
Author(s):  
David R. Williamson ◽  
Kalyan K. Dewan ◽  
Tanmay Patel ◽  
Catherine M. Wastella ◽  
Gang Ning ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Francisella Tularensis ◽  
Mechanosensitive Channel ◽  
Mammalian Host ◽  
Average Cell Size ◽  
Average Cell ◽  
Content Type ◽  
Hypoosmotic Shock ◽  
Osmotic Downshock

ABSTRACTFrancisella tularensissubsp.holarcticais found in North America and much of Europe and causes the disease tularemia in humans and animals. An aquatic cycle has been described for this subspecies, which has caused waterborne outbreaks of tularemia in at least 10 countries. In this study, we sought to identify the mechanosensitive channel(s) required for the bacterium to survive the transition from mammalian hosts to freshwater, which is likely essential for the transmission of the bacterium between susceptible hosts. A single 165-amino-acid MscS-type mechanosensitive channel (FtMscS) was found to protectF. tularensissubsp.holarcticafrom hypoosmotic shock, despite lacking much of the cytoplasmic vestibule domain found in well-characterized MscS proteins from other organisms. The deletion of this channel did not affect virulence within the mammalian host; however,FtMscS was required to survive the transition from the host niche to freshwater. The deletion ofFtMscS did not alter the sensitivity ofF. tularensissubsp.holarcticato detergents, H2O2, or antibiotics, suggesting that the role ofFtMscS is specific to protection from hypoosmotic shock. The deletion ofFtMscS also led to a reduced average cell size without altering gross cell morphology. The mechanosensitive channel identified and characterized in this study likely contributes to the transmission of tularemia between hosts by allowing the bacterium to survive the transition from mammalian hosts to freshwater.IMPORTANCEThe contamination of freshwater byFrancisella tularensissubsp.holarcticahas resulted in a number of outbreaks of tularemia. Invariably, the contamination originates from the carcasses or excreta of infected animals and thus involves an abrupt osmotic downshock as the bacteria enter freshwater. HowF. tularensissurvives this drastic change in osmolarity has not been clear, but here we report that a single mechanosensitive channel protects the bacterium from osmotic downshock. This channel is functional despite lacking much of the cytoplasmic vestibule domain that is present in better-studied organisms such asEscherichia coli; this report builds on previous studies that have suggested that parts of this domain are dispensable for downshock protection. These findings extend our understanding of the aquatic cycle and ecological persistence ofF. tularensis, with further implications for mechanosensitive channel biology.

Efficient utilization of cassava pulp for succinate production by metabolically engineered Escherichia coli KJ122

2014 ◽  
Vol 38 (1) ◽  
pp. 175-187 ◽  
Author(s):  
Apichai Sawisit ◽  
Sirima Suvarnakuta Jantama ◽  
Sunthorn Kanchanatawee ◽  
Kaemwich Jantama
Keyword(s):  
Escherichia Coli ◽  
Efficient Utilization ◽  
Succinate Production ◽  
Cassava Pulp ◽  
Engineered Escherichia Coli ◽  
Metabolically Engineered Escherichia Coli

scholarly journals Elongation Factor Tu and DnaK Are Transferred from the Cytoplasm to the Periplasm of Escherichia coli during Osmotic Downshock Presumably via the Mechanosensitive Channel MscL

2000 ◽  
Vol 182 (1) ◽  
pp. 248-251 ◽  
Author(s):  
Catherine Berrier ◽  
Alexia Garrigues ◽  
Gilbert Richarme ◽  
Alexandre Ghazi
Keyword(s):  
Escherichia Coli ◽  
Plasma Membrane ◽  
Elongation Factor ◽  
Mechanosensitive Channel ◽  
Elongation Factor Tu ◽  
Intact Cells ◽  
Unknown Mechanism ◽  
Cytoplasmic Proteins ◽  
Gene Coding ◽  
Osmotic Downshock

ABSTRACT Upon osmotic downshock, a few cytoplasmic proteins, including thioredoxin, elongation factor Tu (EF-Tu), and DnaK, are released from Tris-EDTA-treated Escherichia coli cells by an unknown mechanism. We have shown previously that deletion of mscL, the gene coding for the mechanosensitive channel of the plasma membrane with the highest conductance, prevents the release of thioredoxin. We confirm and extend the implication of MscL in this process by showing that the release of EF-Tu and DnaK is severely impaired in MscL-deficient strains. Release of these proteins is not observed in the absence of a Tris-EDTA treatment which disrupts the outer membrane, indicating that, in intact cells, they are transferred to the periplasm upon shock, presumably through the MscL channel.

Efficient utilization of Escherichia coli transcriptional signals in Bacillus subtilis

1985 ◽  
Vol 186 (3) ◽  
pp. 547-555 ◽  
Author(s):  
Ursula Peschke ◽  
Verena Beuck ◽  
Hermann Bujard ◽  
Reiner Gentz ◽  
Stuart Le Grice
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Efficient Utilization

Structural organization of escherichia coli ribosomes as determined by immuno electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 166-167 ◽  
Author(s):  
G. Stöffler ◽  
R.W. Bald ◽  
J. Dieckhoff ◽  
H. Eckhard ◽  
R. Lührmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Ribosomal Subunit ◽  
Spatial Arrangement ◽  
Small Subunit ◽  
Antibody Binding ◽  
Immuno Electron Microscopy

A central step towards an understanding of the structure and function of the Escherichia coli ribosome, a large multicomponent assembly, is the elucidation of the spatial arrangement of its 54 proteins and its three rRNA molecules. The structural organization of ribosomal components has been investigated by a number of experimental approaches. Specific antibodies directed against each of the 54 ribosomal proteins of Escherichia coli have been performed to examine antibody-subunit complexes by electron microscopy. The position of the bound antibody, specific for a particular protein, can be determined; it indicates the location of the corresponding protein on the ribosomal surface.The three-dimensional distribution of each of the 21 small subunit proteins on the ribosomal surface has been determined by immuno electron microscopy: the 21 proteins have been found exposed with altogether 43 antibody binding sites. Each one of 12 proteins showed antibody binding at remote positions on the subunit surface, indicating highly extended conformations of the proteins concerned within the 30S ribosomal subunit; the remaining proteins are, however, not necessarily globular in shape (Fig. 1).

Sign in / Sign up

Export Citation Format

Share Document