Analysis of a chemotaxis operon from Rhodospirillum centenum

Jiang, Zeyu; Bauer, Carl E.

doi:10.1128/jb.179.18.5712-5719.1997

Cited by 41 publications

(42 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If so, then disruption of cheY may have a significant effect only on swarmer cell motility. While we have no direct evidence for the existence of separate motors, sequence comparison of the motor docking domains of CheY and CheAY indicated that they are quite different (see the accompanying report [15]). …”

Section: Discussionmentioning

confidence: 99%

“…An added complexity is presented by the control of rotations of lateral and polar flagella, which appear to utilize different structural components (13,34). To examine some of these issues, we have undertaken a mutational analysis of the R. centenum chemotaxis signal transduc-tion cascade, which exhibits several unique features (see the accompanying report [15]). For this analysis, we used reverse genetics techniques to construct nonpolar insertion mutants in individual genes in the che operon.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Chemosensory and photosensory perception in purple photosynthetic bacteria utilize common signal transduction components

1997

Self Cite

View full text Add to dashboard Cite

The chemotaxis gene cluster from the photosynthetic bacterium Rhodospirillum centenum contains five open reading frames (ORFs) that have significant sequence homology to chemotaxis genes from other bacteria. To elucidate the functions of each ORF, we have made various mutations in the gene cluster and analyzed their phenotypic defects. Deletion of the entire che operon (⌬che), as well as nonpolar disruptions of cheAY, cheW, and cheR, resulted in a smooth-swimming phenotype, whereas disruption of cheB resulted in a locked tumbly phenotype. Each of these mutants was defective in chemotactic response. Interestingly, disruption of cheY resulted in a slight increase in the frequency of tumbling/reversal with no obvious defects in chemotactic response. In contrast to observations with Escherichia coli and several other bacteria, we found that all of the che mutant cells were capable of differentiating into hyperflagellated swarmer cells when plated on a solid agar surface. When viewed microscopically, the smooth-swimming che mutants exhibited active surface motility but were unable to respond to a step-down in light intensity. Both positive and negative phototactic responses were abolished in all che mutants, including the cheY mutant. These results indicate that eubacterial photosensory perception is mediated by light-generated signals that are transmitted through the chemotaxis signal transduction cascade.

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Chemosensory and photosensory perception in purple photosynthetic bacteria utilize common signal transduction components

1997

Self Cite

View full text Add to dashboard Cite

show abstract

“…Moreover, 50% to 60% of mesophilic aeromonads are able to produce many unsheathed peritrichous lateral flagella when grown in viscous environments or over surfaces (58), which increase bacterial adherence and are required for swarming motility and biofilm formation (23). The expression of two distinct flagellar systems is relatively uncommon, although it has been observed with Vibrio parahaemolyticus (39), Azospirillum brasilense (45), Rhodospirillum centenum (32), Helicobacter mustelae (49), and Plesiomonas shigelloides (29).…”

mentioning

confidence: 99%

Polar Flagellum Biogenesis inAeromonas hydrophila

et al. 2006

View full text Add to dashboard Cite

Mesophilic Aeromonas spp. constitutively express a single polar flagellum that helps the bacteria move to more favorable environments and is an important virulence and colonization factor. Certain strains can also produce multiple lateral flagella in semisolid media or over surfaces. We have previously reported 16 genes ( flgN to flgL) that constitute region 1 of the Aeromonas hydrophila AH-3 polar flagellum biogenesis gene clusters. We identified 39 new polar flagellum genes distributed in four noncontiguous chromosome regions (regions 2 to 5). Region 2 contained six genes ( flaA to maf-1), including a modification accessory factor gene (maf-1) that has not been previously reported and is thought to be involved in glycosylation of polar flagellum filament. Region 3 contained 29 genes ( fliE to orf29), most of which are involved in flagellum basal body formation and chemotaxis. Region 4 contained a single gene involved in the motor stator formation (motX), and region 5 contained the three master regulatory genes for the A. hydrophila polar flagella ( flrA to flrC). Mutations in the flaH, maf-1, fliM, flhA, fliA, and flrC genes, as well as the double mutant flaA flaB, all caused loss of polar flagella and reduction in adherence and biofilm formation. A defined mutation in the pomB stator gene did not affect polar flagellum motility, in contrast to the motX mutant, which was unable to swim even though it expressed a polar flagellum. Mutations in all of these genes did not affect lateral flagellum synthesis or swarming motility, showing that both A. hydrophila flagellum systems are entirely distinct.Flagellar motility represents an important advantage for bacteria in moving toward favorable conditions or in avoiding detrimental environments, and it allows flagellated bacteria to successfully compete with other microorganisms (21). In addition, motility and flagella play a crucial role in adhesion, biofilm formation, and colonization of several pathogenic bacteria, such as Pseudomonas aeruginosa (59), Salmonella enterica (13), Escherichia coli (51), Helicobacter pylori (19), Vibrio cholerae (22), and Aeromonas hydrophila (43,53).Mesophilic Aeromonas spp. are ubiquitous waterborne bacteria and pathogens of reptiles, amphibians, and fish (5). They can be isolated as a part of the fecal flora of a wide variety of other animals, including some used for human consumption, such as pigs, cows, sheep, and poultry. In humans, Aeromonas hydrophila belonging to hybridization group 1 (HG1) and HG3, A. veronii biovar sobria (HG8/HG10), and A. caviae (HG4) have been associated with gastrointestinal and extraintestinal diseases, such as wound infections of healthy humans, and less commonly with septicemia of immunocompromised patients (30). The swimming motility of all mesophilic aeromonads has been linked to a single polar unsheathed flagellum, expressed constitutively, which is required for adherence to and invasion of human and fish cell lines (25,43,53,63). Moreover, 50% to 60% of mesophilic aeromonads are able to produce many...

show abstract

“…The expression of two distinct flagellar systems is relatively uncommon, although it has been observed in Vibrio parahaemolyticus (19), Azospirillum brasilense (26), Rhodospirillum centenum (15), Helicobacter mustelae (29), and Plesiomonas shigelloides (13). V. parahaemolyticus is the best-studied organism, and it has two distinct flagellar systems.…”

mentioning

confidence: 99%

Analysis of the Lateral Flagellar Gene System ofAeromonas hydrophilaAH-3

et al. 2006

View full text Add to dashboard Cite

Mesophilic Aeromonas strains express a polar flagellum in all culture conditions, and certain strains produce lateral flagella on semisolid media or on surfaces. Although Aeromonas lateral flagella have been described as a colonization factor, little is known about their organization and expression. Here we characterized the complete lateral flagellar gene cluster of Aeromonas hydrophila AH-3 containing 38 genes, 9 of which (lafA-U) have been reported previously. Among the flgL L and lafA structural genes we found a modification accessory factor gene (maf-5) that is involved in formation of lateral flagella; this is the first time that such a gene has been described for lateral flagellar gene systems. All Aeromonas lateral flagellar genes were located in a unique chromosomal region, in contrast to Vibrio parahaemolyticus, in which the analogous genes are distributed in two different chromosomal regions. In A. hydrophila mutations in flhA L , lafK, fliJ L , flgN L , flgE L , and maf-5 resulted in a loss of lateral flagella and reductions in adherence and biofilm formation, but they did not affect polar flagellum synthesis. Furthermore, we also cloned and sequenced the A. hydrophila AH-3 alternative sigma factor 54 (rpoN); mutation of this factor suggested that it is involved in expression of both types of flagella.Mesophilic Aeromonas strains are ubiquitous waterborne bacteria and pathogens of reptiles, amphibians, and fish (4). They can be isolated as part of the fecal flora of a wide variety of other animals, including some animals consumed by humans, such pigs, cows, sheep, and poultry. In humans, Aeromonas hydrophila strains belonging to hybridization group 1 (HG1) and HG3, Aeromonas veronii biovar sobria (HG8/ HG10), and Aeromonas caviae (HG4) have been associated with gastrointestinal and extraintestinal diseases, such as wound infections, and less commonly with septicemias of immunocompromised patients (14). The pathogenicity of mesophilic aeromonads has been linked to a number of different determinants, such as toxins, proteases, outer membrane proteins (28), lipopolysaccharide (23), and flagella (23, 32).Mesophilic Aeromonas strains usually have a single polar unsheathed flagellum in all culture conditions, but it is known that 50% to 60% of the mesophilic aeromonads most commonly associated with diarrhea (18) also have many unsheathed peritrichous lateral flagella when they are grown in viscous environments or on surfaces (38). Different workers have shown that lateral flagella increase bacterial adherence and are required for swarming motility and biofilm formation (10, 19).The expression of two distinct flagellar systems is relatively uncommon, although it has been observed in Vibrio parahaemolyticus (19), Azospirillum brasilense (26), Rhodospirillum centenum (15), Helicobacter mustelae (29), and Plesiomonas shigelloides (13). V. parahaemolyticus is the best-studied organism, and it has two distinct flagellar systems. Recently, an Escherichia coli O42 lateral flagellar gene cluster (Flag-2) has been d...

show abstract

Analysis of a chemotaxis operon from Rhodospirillum centenum

Cited by 41 publications

References 46 publications

Chemosensory and photosensory perception in purple photosynthetic bacteria utilize common signal transduction components

Chemosensory and photosensory perception in purple photosynthetic bacteria utilize common signal transduction components

Polar Flagellum Biogenesis inAeromonas hydrophila

Analysis of the Lateral Flagellar Gene System ofAeromonas hydrophilaAH-3

Contact Info

Product

Resources

About