Flagellar motors of marine bacteria Halomonas are driven by both protons and sodium ions

2004 ◽  
Vol 50 (5) ◽  
pp. 369-374 ◽  
Author(s):  
K Kita-Tsukamoto ◽  
M Wada ◽  
K Yao ◽  
T Nishino ◽  
K Kogure
Keyword(s):  
Marine Bacteria ◽  
Specific Inhibitor ◽  
Proton Conductor ◽  
Bacterial Cells ◽  
Flagellar Motor ◽  
Sodium Ions ◽  
Ion Specificity ◽  
Nutrient Patches ◽  
Flagellar Motors ◽  
Wide Range

Bacterial cells in aquatic environments are able to reach or stay near nutrient patches by using motility. Motility is usually attained by rotating flagellar motors that are energized by electrochemical potential of H+ or Na+. In this paper, the ion specificity for flagellar rotation of two marine isolates Halomonas spp. strains US172 and US201 was investigated. Both isolates require sodium for growth and possess a respiratory-driven primary sodium pump. They are motile because of lateral flagella regardless of the presence of sodium ions. Their swimming speed under various concentrations of sodium ions with and without carbonylcyanide m-chlorophenylhydrazone, a proton conductor, and with and without phenamil, a specific inhibitor for the sodium-driven flagellar motors, was examined. The effect of carbonylcyanide m-chlorophenylhydrazone on the transmembrane proton gradient was also determined. Our results showed that the flagellar motors of the Halomonas strains were energized by both H+ and Na+ in one cell. The bimodal nature of Halomonas spp. motility with respect to the driving energy source may reflect ecophysiological versatility to adapt to a wide range of salt conditions of the marine environment.Key words: marine bacteria, Halomonas, flagellar motor, sodium, proton.

scholarly journals Tuning the flagellar motor

Microbiology ◽  
2010 ◽  
Vol 156 (5) ◽  
pp. 1275-1283 ◽  
Author(s):  
Kai M. Thormann ◽  
Anja Paulick
Keyword(s):  
Cell Wall ◽  
Environmental Conditions ◽  
Survival Advantage ◽  
Sodium Ion ◽  
Flagellar Motor ◽  
Numerous Species ◽  
Flagellar Motors ◽  
Wide Range ◽  
Flagellar Rotation

Many bacteria are motile by means of flagella, semi-rigid helical filaments rotated at the filament's base and energized by proton or sodium-ion gradients. Torque is created between the two major components of the flagellar motor: the rotating switch complex and the cell-wall-associated stators, which are arranged in a dynamic ring-like structure. Being motile provides a survival advantage to many bacteria, and thus the flagellar motor should work optimally under a wide range of environmental conditions. Recent studies have demonstrated that numerous species possess a single flagellar system but have two or more individual stator systems that contribute differentially to flagellar rotation. This review describes recent findings on rotor–stator interactions, on the role of different stators, and on how stator selection could be regulated. An emerging model suggests that bacterial flagellar motors are dynamic and can be tuned by stator swapping in response to different environmental conditions.

scholarly journals Stator Dynamics Depending on Sodium Concentration in Sodium-Driven Bacterial Flagellar Motors

2021 ◽  
Vol 12 ◽  
Author(s):  
Tsai-Shun Lin ◽  
Seiji Kojima ◽  
Hajime Fukuoka ◽  
Akihiko Ishijima ◽  
Michio Homma ◽  
...  
Keyword(s):  
Exchange Process ◽  
Sodium Concentration ◽  
Motive Force ◽  
Flagellar Motor ◽  
Rotary Machine ◽  
Low Sodium ◽  
Flagellar Motors ◽  
Wide Range ◽  
Membrane Spanning ◽  
Fast Perfusion

Bacterial flagellar motor (BFM) is a large membrane-spanning molecular rotary machine for swimming motility. Torque is generated by the interaction between the rotor and multiple stator units powered by ion-motive force (IMF). The number of bound stator units is dynamically changed in response to the external load and the IMF. However, the detailed dynamics of stator unit exchange process remains unclear. Here, we directly measured the speed changes of sodium-driven chimeric BFMs under fast perfusion of different sodium concentration conditions using computer-controlled, high-throughput microfluidic devices. We found the sodium-driven chimeric BFMs maintained constant speed over a wide range of sodium concentrations by adjusting stator units in compensation to the sodium-motive force (SMF) changes. The BFM has the maximum number of stator units and is most stable at 5 mM sodium concentration rather than higher sodium concentration. Upon rapid exchange from high to low sodium concentration, the number of functional stator units shows a rapidly excessive reduction and then resurrection that is different from predictions of simple absorption model. This may imply the existence of a metastable hidden state of the stator unit during the sudden loss of sodium ions.

scholarly journals The structural complexity of the Gammaproteobacteria flagellar motor is related to the type of its torque-generating stators

2018 ◽  
Author(s):  
Mohammed Kaplan ◽  
Debnath Ghosal ◽  
Poorna Subramanian ◽  
Catherine M. Oikonomou ◽  
Andreas Kjær ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Pathogenic Bacteria ◽  
Cell Envelope ◽  
Shewanella Oneidensis ◽  
Structural Complexity ◽  
High Viscosity ◽  
Flagellar Motor ◽  
Flagellar Motors ◽  
Wide Range ◽  
A Cell

AbstractThe bacterial flagellar motor is a cell-envelope-embedded macromolecular machine that functions as a propeller to move the cell. Rather than being an invariant machine, the flagellar motor exhibits significant variability between species, allowing bacteria to adapt to, and thrive in, a wide range of environments. For instance, different torque-generating stator modules allow motors to operate in conditions with different pH and sodium concentrations and some motors are adapted to drive motility in high-viscosity environments. How such diversity evolved is unknown. Here we use electron cryo-tomography to determine thein situmacromolecular structures of the flagellar motors of three Gammaproteobacteria species:Legionella pneumophila,Pseudomonas aeruginosa, andShewanella oneidensisMR-1, providing the first views of intact motors with dual stator systems. Complementing our imaging with bioinformatics analysis, we find a correlation between the stator system of the motor and its structural complexity. Motors with a single H+-driven stator system have only the core P- and L-rings in their periplasm; those with dual H+-driven stator systems have an extra component elaborating their P-ring; and motors with Na+- (or dual Na+-H+)- driven stator systems have additional rings surrounding both their P- and L-rings. Our results suggest an evolution of structural complexity that may have enabled pathogenic bacteria likeL. pneumophilaandP. aeruginosato colonize higher-viscosity environments in animal hosts.

Genetic engineering: possibilities and prospects for its application in industrial microbiology

1980 ◽  
Vol 290 (1040) ◽  
pp. 369-386 ◽  
Keyword(s):  
Escherichia Coli ◽  
Genetic Engineering ◽  
Detailed Analysis ◽  
Bacterial Cells ◽  
Bacterial Enzymes ◽  
Distant Future ◽  
Cells In Culture ◽  
Wide Range ◽  
Hybrid Dna

A wide range of techniques is now available for the construction of hybrid DNA molecules comprising components from disparate species. Transfer of segments of DNA from other organisms, and especially eukaryotes, to Escherichia coli permits their preparation in quantities sufficient for detailed analysis of their structure and mechanism of expression. This information could be exploited to enhance the quantity or quality of polypeptide products from bacterial cells. Greatly increased yields of bacterial enzymes have been obtained in this way in several instances. The approaches that have been pioneered with bacteria are currently being applied to higher organisms. Much work is in progress with yeasts, in which transformation has been successfully demonstrated, with animal viruses and cells in culture and with some plant systems and offers the promise of wider applications of genetic engineering in the not too distant future.

scholarly journals The presence and absence of periplasmic rings in bacterial flagellar motors correlates with stator type

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Mohammed Kaplan ◽  
Debnath Ghosal ◽  
Poorna Subramanian ◽  
Catherine M Oikonomou ◽  
Andreas Kjaer ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Pathogenic Bacteria ◽  
Bioinformatics Analysis ◽  
Cell Envelope ◽  
Shewanella Oneidensis ◽  
Flagellar Motor ◽  
Flagellar Motors ◽  
A Cell ◽  
Animal Hosts

The bacterial flagellar motor, a cell-envelope-embedded macromolecular machine that functions as a cellular propeller, exhibits significant structural variability between species. Different torque-generating stator modules allow motors to operate in different pH, salt or viscosity levels. How such diversity evolved is unknown. Here, we use electron cryo-tomography to determine the in situ macromolecular structures of three Gammaproteobacteria motors: Legionella pneumophila, Pseudomonas aeruginosa, and Shewanella oneidensis, providing the first views of intact motors with dual stator systems. Complementing our imaging with bioinformatics analysis, we find a correlation between the motor’s stator system and its structural elaboration. Motors with a single H+-driven stator have only the core periplasmic P- and L-rings; those with dual H+-driven stators have an elaborated P-ring; and motors with Na+ or Na+/H+-driven stators have both their P- and L-rings embellished. Our results suggest an evolution of structural elaboration that may have enabled pathogenic bacteria to colonize higher-viscosity environments in animal hosts.

scholarly journals Plasticity in Escherichia coli cell wall metabolism promotes fitness and mediates intrinsic antibiotic resistance across environmental conditions

2018 ◽  
Author(s):  
Elizabeth A Mueller ◽  
Petra Anne Levin
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Growth Parameter ◽  
Culture Conditions ◽  
Cell Wall Integrity ◽  
Bacterial Cells ◽  
Intrinsic Resistance ◽  
Wide Range ◽  
Peptidoglycan Cell Wall ◽  
Wide Ph Range

ABSTRACTAlthough the peptidoglycan cell wall is an essential structural and morphological feature of most bacterial cells, the extracytoplasmic enzymes involved in its synthesis are frequently dispensable under standard culture conditions. By modulating a single growth parameter—extracellular pH—we discovered a subset of these so-called “redundant” enzymes in Escherichia coli are required for maximal fitness across pH environments. Among these pH specialists are the class A penicillin binding proteins PBP1 a and PBP1 b; defects in these enzymes attenuate growth in alkaline and acidic conditions, respectively. Genetic, biochemical, and cytological studies demonstrate that synthase activity is required for cell wall integrity across a wide pH range, and differential activity across pH environments significantly alters intrinsic resistance to cell wall active antibiotics. Together, our findings reveal previously thought to be redundant enzymes are instead specialized for distinct environmental niches, thereby ensuring robust growth and cell wall integrity in a wide range of conditions.

scholarly journals Supramolecular Fuzziness of Intracellular Liquid Droplets: Liquid–Liquid Phase Transitions, Membrane-Less Organelles, and Intrinsic Disorder

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3265 ◽  
Author(s):  
Vladimir N. Uversky
Keyword(s):  
Phase Transitions ◽  
Liquid Phase ◽  
Intrinsically Disordered Proteins ◽  
Intrinsically Disordered Protein ◽  
Disordered Proteins ◽  
Bacterial Cells ◽  
Liquid Droplets ◽  
Intrinsically Disordered ◽  
Wide Range ◽  
Characteristic Features

Cells are inhomogeneously crowded, possessing a wide range of intracellular liquid droplets abundantly present in the cytoplasm of eukaryotic and bacterial cells, in the mitochondrial matrix and nucleoplasm of eukaryotes, and in the chloroplast’s stroma of plant cells. These proteinaceous membrane-less organelles (PMLOs) not only represent a natural method of intracellular compartmentalization, which is crucial for successful execution of various biological functions, but also serve as important means for the processing of local information and rapid response to the fluctuations in environmental conditions. Since PMLOs, being complex macromolecular assemblages, possess many characteristic features of liquids, they represent highly dynamic (or fuzzy) protein–protein and/or protein–nucleic acid complexes. The biogenesis of PMLOs is controlled by specific intrinsically disordered proteins (IDPs) and hybrid proteins with ordered domains and intrinsically disordered protein regions (IDPRs), which, due to their highly dynamic structures and ability to facilitate multivalent interactions, serve as indispensable drivers of the biological liquid–liquid phase transitions (LLPTs) giving rise to PMLOs. In this article, the importance of the disorder-based supramolecular fuzziness for LLPTs and PMLO biogenesis is discussed.

scholarly journals Proteorhodopsin Overproduction Enhances the Long-Term Viability of Escherichia coli

2019 ◽  
Vol 86 (1) ◽  
Author(s):  
Yizhi Song ◽  
Michaël L. Cartron ◽  
Philip J. Jackson ◽  
Paul A. Davison ◽  
Mark J. Dickman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Raman Spectroscopy ◽  
Cell Membrane ◽  
Single Cell ◽  
Marine Bacteria ◽  
Membrane Area ◽  
Content Type ◽  
E Coli ◽  
Wide Range

ABSTRACT Genes encoding the photoreactive protein proteorhodopsin (PR) have been found in a wide range of marine bacterial species, reflecting the significant contribution that PR makes to energy flux and carbon cycling in ocean ecosystems. PR can also confer advantages to enhance the ability of marine bacteria to survive periods of starvation. Here, we investigate the effect of heterologously produced PR on the viability of Escherichia coli. Quantitative mass spectrometry shows that E. coli, exogenously supplied with the retinal cofactor, assembles as many as 187,000 holo-PR molecules per cell, accounting for approximately 47% of the membrane area; even cells with no retinal synthesize ∼148,000 apo-PR molecules per cell. We show that populations of E. coli cells containing PR exhibit significantly extended viability over many weeks, and we use single-cell Raman spectroscopy (SCRS) to detect holo-PR in 9-month-old cells. SCRS shows that such cells, even incubated in the dark and therefore with inactive PR, maintain cellular levels of DNA and RNA and avoid deterioration of the cytoplasmic membrane, a likely basis for extended viability. The substantial proportion of the E. coli membrane required to accommodate high levels of PR likely fosters extensive intermolecular contacts, suggested to physically stabilize the cell membrane and impart a long-term benefit manifested as extended viability in the dark. We propose that marine bacteria could benefit similarly from a high PR content, with a stabilized cell membrane extending survival when those bacteria experience periods of severe nutrient or light limitation in the oceans. IMPORTANCE Proteorhodopsin (PR) is part of a diverse, abundant, and widespread superfamily of photoreactive proteins, the microbial rhodopsins. PR, a light-driven proton pump, enhances the ability of the marine bacterium Vibrio strain AND4 to survive and recover from periods of starvation, and heterologously produced PR extends the viability of nutrient-limited Shewanella oneidensis. We show that heterologously produced PR enhances the viability of E. coli cultures over long periods of several weeks and use single-cell Raman spectroscopy (SCRS) to detect PR in 9-month-old cells. We identify a densely packed and consequently stabilized cell membrane as the likely basis for extended viability. Similar considerations are suggested to apply to marine bacteria, for which high PR levels represent a significant investment in scarce metabolic resources. PR-stabilized cell membranes in marine bacteria are proposed to keep a population viable during extended periods of light or nutrient limitation, until conditions improve.

scholarly journals Biphasic chemotaxis ofEscherichia colito the microbiota metabolite indole

2020 ◽  
Vol 117 (11) ◽  
pp. 6114-6120 ◽  
Author(s):  
Jingyun Yang ◽  
Ravi Chawla ◽  
Kathy Y. Rhee ◽  
Rachit Gupta ◽  
Michael D. Manson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Microbial Communities ◽  
Bacterial Chemotaxis ◽  
Dynamic Responses ◽  
Time Dependent ◽  
Flagellar Motor ◽  
Wild Type ◽  
Gi Tract ◽  
Flagellar Motors

Bacterial chemotaxis to prominent microbiota metabolites such as indole is important in the formation of microbial communities in the gastrointestinal (GI) tract. However, the basis of chemotaxis to indole is poorly understood. Here, we exposedEscherichia colito a range of indole concentrations and measured the dynamic responses of individual flagellar motors to determine the chemotaxis response. Below 1 mM indole, a repellent-only response was observed. At 1 mM indole and higher, a time-dependent inversion from a repellent to an attractant response was observed. The repellent and attractant responses were mediated by the Tsr and Tar chemoreceptors, respectively. Also, the flagellar motor itself mediated a repellent response independent of the receptors. Chemotaxis assays revealed that receptor-mediated adaptation to indole caused a bipartite response—wild-type cells were attracted to regions of high indole concentration if they had previously adapted to indole but were otherwise repelled. We propose that indole spatially segregates cells based on their state of adaptation to repel invaders while recruiting beneficial resident bacteria to growing microbial communities within the GI tract.

NUTRITION AND METABOLISM OF MARINE BACTERIA: XI. SOME CHARACTERISTICS OF THE LYTIC PHENOMENON

1962 ◽  
Vol 8 (6) ◽  
pp. 883-896 ◽  
Author(s):  
Robert A. MacLeod ◽  
Tibor I. Matula
Keyword(s):  
Cell Wall ◽  
Marine Bacteria ◽  
Divalent Cations ◽  
Morphological Characteristics ◽  
Bacterial Cells ◽  
Whole Cells ◽  
Lytic Action ◽  
Absorbing Materials ◽  
Sulphate Salts ◽  
Osmotic Effects

Five marine bacteria examined were found to differ considerably in lytic susceptibility. Some lysed completely below 0.15 M NaCl while suspensions of others contained some whole cells at 0.025 M NaCl. In general NaCl and LiCl were more effective than KCl or NH4Cl in protecting against lysis and the loss of ultraviolet-absorbing materials from the cells. KCl could spare the requirement for NaCl to prevent lysis. Mg++ and other divalent cations at 0.05 M or less completely prevented lysis of all but one of the organisms. Sulphate salts stabilized the cell suspensions better on incubation than did chlorides for four of the organisms. For the fifth the reverse was true. The lytic action of ethanol and glycerol could be prevented by NaCl or sucrose. The concentrations of the latter required to prevent lysis remained unchanged when ethanol or glycerol was included in the suspending medium. Cells washed essentially free of electrolytes with 0.5 M sucrose retained their morphological characteristics. The observations are considered in relation to the distinction between marine bacteria, halophiles, and terrestrial bacteria and to current theories of the mechanism of lysis of bacterial cells. The results are not consistent with the hypotheses either that primarily osmotic effects are involved or that electrolytes are required to maintain the cell wall.

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