Disease relevance of yaiU

• The ability of E. coli to adapt to constant levels of attractant and repellent chemicals was studied by examining the patterns of flagellar movement in cells subjected to abrupt concentration changes [1].
• The flagellar anti-sigma factor FlgM actively dissociates Salmonella typhimurium sigma28 RNA polymerase holoenzyme [2].
• Inversions of specific DNA segments in flagellar phase variation of Salmonella and inversion systems of bacteriophages P1 and Mu [3].
• The structure of the helically perturbed flagellar filament of Pseudomonas rhodos: implications for the absence of the outer domain in other complex flagellins and for the flexibility of the radial spokes [4].
• In enterobacteria such as Salmonella, flagellar biogenesis is dependent upon the master operon flhDC at the apex of the flagellar gene hierarchy, which is divided into three classes 1, 2 and 3 [5].

Psychiatry related information on yaiU

• The best-oriented flagellar sol showed a disorientation angle of 0.6 degrees as 1sigma of its Gaussian distribution [6].

High impact information on yaiU

• The sensory adaptation defect of cheX strains may be due to an inability to methylate several cytoplasmic membrane proteins that initiate changes in flagellar movement in response to chemoreceptor signals [1].
• Lowe et al. analysed the frequency of light scattered from swimming cells to estimate the average rotation speed of flagellar bundles of E. coli as about 270 r.p.s. To analyse motor function in more detail, however, measurement of high-speed rotation of a single flagellum (at low load) with a temporal resolution better than 1 ms is needed [7].
• We propose that this secondary activity of FlgM, which we term holoenzyme destabilization, enhances the sensitivity of the cell to changes in FlgM levels during flagellar biogenesis [2].
• Stimulation of the Ipaf pathway in macrophages after infection required a functional salmonella pathogenicity island 1 type III secretion system but not the flagellar type III secretion system; furthermore, Ipaf activation could be recapitulated by the introduction of purified flagellin directly into the cytoplasm [8].
• According to the cascade model of flagellar regulon, the flagellar operons are divided into three classes, 1, 2, and 3, with respect to transcriptional hierarchy [9].

Chemical compound and disease context of yaiU

• Azithromycin inhibits the formation of flagellar filaments without suppressing flagellin synthesis in Salmonella enterica serovar typhimurium [10].
• In Escherichia coli and Salmonella typhimurium, ATP is required for chemotaxis and for a normal probability of clockwise rotation of the flagellar motors, in addition to the requirement for S-adenosylmethionine (J. Shioi, R. J. Galloway, M. Niwano, R. E. Chinnock, and B. L. Taylor, J. Biol. Chem. 257:7969-7975, 1982) [11].
• Tyrosine is essential for flagellin, which is the subunit of the salmonella flagellar filament [12].

Biological context of yaiU

• Examination of the behavior of various mutants shows that the flagellar apparatus used for swimming motility and the chemotaxis system are indispensable for swarming motility [13].
• The resulting hybrid plasmid, pKK2, was shown to possess the din+ activity: the vh2 mutant of Salmonella harboring the plasmid changed the flagellar phase [3].
• The flrA and flrC gene products are sigma54-activators and form a flagellar transcription cascade. flrA and flrC mutants are also defective for colonization; this phenotype is probably independent of non-motility [14].
• Although swarming-specific induction of flagellar gene expression was not generally apparent, genes for iron metabolism were strongly induced specifically on swarm agar [15].
• Thus, sigma54 holoenzyme, FlrA and FlrC transcribe genes for flagellar synthesis and possibly cell division during the free-swimming phase of the V. cholerae life cycle, and some as yet unidentified gene(s) that aid colonization within the host [14].

Anatomical context of yaiU

• Here, we demonstrate that a significant fraction of Salmonella-specific CD4+ T cells respond to the flagellar filament protein, FliC, and that this Ag has the capacity to protect naive mice from lethal Salmonella infection [16].
• In addition, flagellar cytoplasmic structure could be isolated from B. firmus [17].
• Conversely, the presence of flagella is required for the full invasive potential of the bacterium in tissue culture and for the influx of polymorphonuclear leukocytes in the calf intestine, while the flagellar secretory components are also necessary for the induction of maximum fluid secretion in that enterocolitis model [18].
• We found that serovar Typhi strains carrying a null mutation in either of the flagellar regulatory genes flhDC or fliA were severely deficient in entry into cultured epithelial cells and macrophage cytotoxicity [19].
• Premature polymerization of flagellin (FliC), the main component of flagellar filaments, is prevented by the FliS chaperone in the cytosol [20].

Associations of yaiU with chemical compounds

• Alanine replacement of amino acids 30-42 (and to some extent 44-54) abolished tight InvB binding, abolished translocation into the host cell and led to secretion of SopE via both, the flagellar and the SPI-1 TTSS [21].
• Terminal regions of flagellin, about 180 NH2 and 100 COOH-terminal residues, are well conserved and play important roles in polymerization and polymorphism of bacterial flagellar filaments [22].
• However, histidine-starved cheZs hisF strains were not defective in flagellar function or the tumbling mechanism since freshly starved auxotrophs tumbled in response to a variety of repellents [23].
• A conditional-lethal mutant was isolated as having a flagellar regulatory phenotype at 30 degrees C and being unable to grow at 42 degrees C. Chromosomal mapping localized the mutation to the serT gene, which encodes an essential serine tRNA species (tRNA((cmo)5UGA)(Ser)) [24].
• Insertion of a kanamycin-resistant gene cartridge into the chromosomal flhE gene did not affect the motility of the cells, indicating that the flhE gene is not essential for flagellar formation and function [25].

Other interactions of yaiU

• Transcription of the late (Class 3) flagellar promoters in Salmonella typhimurium is dependent upon the flagellar specific sigma factor, sigma28, encoded by the fliA gene. sigma28-dependent transcription is inhibited by an anti-sigma factor, FlgM, through a direct interaction [26].
• Flk couples flgM translation to flagellar ring assembly in Salmonella typhimurium [27].
• The mechanism of suppression of the fliG mutation by the mot mutations is complex, involving destabilization of the right-handed flagellar bundle as a result of reduced motor speed [28].
• Pseudorevertants (second-site suppressor mutants) were isolated from a set of parental mutants of Salmonella with defects in the flagellar switch genes fliG and fliM [28].
• The torque-generating, direction-reversing switch proteins of the bacterial flagellar rotary motor form a cytoplasmic extension of the bacterial flagellar basal body [29].

Analytical, diagnostic and therapeutic context of yaiU

• Monolayer crystallization of flagellar L-P rings by sequential addition and depletion of lipid [30].
• Mass determination and estimation of subunit stoichiometry of the bacterial hook-basal body flagellar complex of Salmonella typhimurium by scanning transmission electron microscopy [31].
• The structure of the R-type straight flagellar filament of Salmonella at 9 A resolution by electron cryomicroscopy [32].
• We have used affinity chromatography for purification of extended flagellar basal bodies sufficient for quantitative analysis of their protein composition [33].
• These mutants lacked motion in liquid culture, were unable to spread on agar plates, and lacked flagellar filaments as determined by electron microscopy [34].

References