| cloning and comparison of flic genes and identification of glycosylation in the flagellin of pseudomonas aeruginosa a-type strains. | pseudomonas aeruginosa a-type strains produce flagellin proteins which vary in molecular weight between strains. to compare the properties of a-type flagellins, the flagellin genes of several pseudomonas aeruginosa a-type strains, as determined by interaction with specific anti-a monoclonal antibody, were cloned and sequenced. pcr amplification of the a-type flagellin gene fragments from five strains each yielded a 1.02-kb product, indicating that the gene size is not likely to be responsible fo ... | 1998 | 9620973 |
| polar flagellar motility of the vibrionaceae. | polar flagella of vibrio species can rotate at speeds as high as 100,000 rpm and effectively propel the bacteria in liquid as fast as 60 microm/s. the sodium motive force powers rotation of the filament, which acts as a propeller. the filament is complex, composed of multiple subunits, and sheathed by an extension of the cell outer membrane. the regulatory circuitry controlling expression of the polar flagellar genes of members of the vibrionaceae is different from the peritrichous system of ent ... | 2001 | 11528005 |
| investigations into the life cycle of the bacterial predator bdellovibrio bacteriovorus 109j at an interface by atomic force microscopy. | atomic force microscopy was used to image bdellovibrio bacteriovorus 109j, a gram-negative bacterial predator that consumes a variety of other gram-negative bacteria. in predator-prey communities grown on filters at hydrated air-solid interfaces, repeated cycles of hunting, invasion, growth, and lysis occurred readily even though the cells were limited to near two-dimensional movement. this system allowed us to image the bacteria directly without extensive preparation or modification, and many o ... | 2003 | 12719266 |
| polarity in action: asymmetric protein localization in bacteria. | | 2001 | 11344132 |
| a persistent and diverse airway microbiota present during chronic obstructive pulmonary disease exacerbations. | acute exacerbations of chronic obstructive pulmonary disease (copd) are a major source of morbidity and contribute significantly to healthcare costs. although bacterial infections are implicated in nearly 50% of exacerbations, only a handful of pathogens have been consistently identified in copd airways, primarily by culture-based methods, and the bacterial microbiota in acute exacerbations remains largely uncharacterized. the aim of this study was to comprehensively profile airway bacterial com ... | 2010 | 20141328 |
| characterization of three different unusual s-layer proteins from viridibacillus arvi jg-b58 that exhibits two super-imposed s-layer proteins. | genomic analyses of viridibacillus arvi jg-b58 that was previously isolated from heavy metal contaminated environment identified three different putative surface layer (s-layer) protein genes namely slp1, slp2, and slp3. all three genes are expressed during cultivation. at least two of the v. arvi jg-b58 s-layer proteins were visualized on the surface of living cells via atomic force microscopy (afm). these s-layer proteins form a double layer with p4 symmetry. the s-layer proteins were isolated ... | 2016 | 27285458 |
| campylobacter fetus meningitis in adults: report of 2 cases and review of the literature. | the zoonotic pathogen campylobacter fetus is a rare cause of bacterial meningitis. little is known about the clinical characteristics, predisposing factors and outcome of c fetus meningitis in adults.we report cases of c fetus meningitis in a nationwide cohort study of adult bacterial meningitis patients in the netherlands and performed a review of the literature.two patients with c fetus meningitis were identified from january 2006 through may 2015. the calculated annual incidence was 0.02 per ... | 2016 | 26937916 |
| non-alcoholic fatty liver and the gut microbiota. | non-alcoholic fatty liver (nafld) is a common, multi-factorial, and poorly understood liver disease whose incidence is globally rising. nafld is generally asymptomatic and associated with other manifestations of the metabolic syndrome. yet, up to 25% of nafld patients develop a progressive inflammatory liver disease termed non-alcoholic steatohepatitis (nash) that may progress towards cirrhosis, hepatocellular carcinoma, and the need for liver transplantation. in recent years, several lines of e ... | 2016 | 27617201 |
| characterizing the s-layer structure and anti-s-layer antibody recognition on intact tannerella forsythia cells by scanning probe microscopy and small angle x-ray scattering. | tannerella forsythia is among the most potent triggers of periodontal diseases, and approaches to understand underlying mechanisms are currently intensively pursued. a ~22-nm-thick, 2d crystalline surface (s-) layer that completely covers tannerella forsythia cells is crucially involved in the bacterium-host cross-talk. the s-layer is composed of two intercalating glycoproteins (tfsa-gp, tfsb-gp) that are aligned into a periodic lattice. to characterize this unique s-layer structure at the nanom ... | 2013 | 24089361 |
| analysis of the cell surface layer ultrastructure of the oral pathogen tannerella forsythia. | the gram-negative oral pathogen tannerella forsythia is decorated with a 2d crystalline surface (s-) layer, with two different s-layer glycoprotein species being present. prompted by the predicted virulence potential of the s-layer, this study focused on the analysis of the arrangement of the individual s-layer glycoproteins by a combination of microscopic, genetic, and biochemical analyses. the two s-layer genes are transcribed into mrna and expressed into protein in equal amounts. the s-layer ... | 2012 | 22273979 |
| structural diversity of bacterial flagellar motors. | the bacterial flagellum is one of nature's most amazing and well-studied nanomachines. its cell-wall-anchored motor uses chemical energy to rotate a microns-long filament and propel the bacterium towards nutrients and away from toxins. while much is known about flagellar motors from certain model organisms, their diversity across the bacterial kingdom is less well characterized, allowing the occasional misrepresentation of the motor as an invariant, ideal machine. here, we present an electron cr ... | 2011 | 21673657 |
| design and performance of a 16s rrna-targeted oligonucleotide probe for detection of members of the genus bdellovibrio by fluorescence in situ hybridization. | a 16s rrna-targeted, cy3-labeled oligonucleotide probe was designed to detect members of the genus bdellovibrio by fluorescence in situ hybridization. specific hybridization conditions were established; however, the detection of bdellovibrios in environmental samples required enrichment, confirming that bdellovibrio spp. are not present in large numbers in the environment. | 2007 | 17905886 |
| denaturing gradient gel electrophoretic analysis of ammonia-oxidizing bacterial community structure in the lower seine river: impact of paris wastewater effluents. | the seine river is strongly affected by the effluents from the acheres wastewater treatment plant (wwtp) downstream of the city of paris. we have shown that the effluents introduce large amounts of ammonia and inoculate the receiving medium with nitrifying bacteria. the aim of the present study was to investigate the diversity of the ammonia-oxidizing bacterial population by identifying autochthonous bacteria from upstream and/or allochthonous ammonia-oxidizing bacteria from the wwtp effluents. ... | 2004 | 15528539 |
| structural analysis and evidence for dynamic emergence of bacillus anthracis s-layer networks. | surface layers (s-layers), which form the outermost layers of many bacteria and archaea, consist of protein molecules arranged in two-dimensional crystalline arrays. bacillus anthracis, a gram-positive, spore-forming bacterium, responsible for anthrax, synthesizes two abundant surface proteins: sap and ea1. regulatory studies showed that ea1 and sap appear sequentially at the surface of the parental strain. sap and ea1 can form arrays. the structural parameters of s-layers from mutant strains (e ... | 2002 | 12426331 |
| effect of purified lipopolysaccharides from strains of helicobacter pylori and helicobacter felis on acid secretion in mouse gastric glands in vitro. | as a bacterial product, helicobacter pylori lipopolysaccharide (lps) can originate in close proximity to parietal cells, but the role of this uniquely structured endotoxin on acid secretion has not been fully investigated and remains unclear. the purpose of this study was to test the direct effect of purified lps (tested range, 0.1 to 100 microg/ml) from various strains of h. pylori and from one helicobacter felis strain on histamine- and carbachol-stimulated acid secretion in vitro using mouse ... | 2001 | 11349056 |
| overexpression of methanococcus voltae flagellin subunits in escherichia coli and pseudomonas aeruginosa: a source of archaeal preflagellin. | methanococcus voltae is a flagellated member of the archaea. four highly similar flagellin genes have previously been cloned and sequenced, and the presence of leader peptides has been demonstrated. while the flagellins of m. voltae are predicted from their gene sequences to be approximately 22 to 25 kda, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) analysis of purified flagella revealed flagellin subunits with apparent molecular masses of 31 and 33 kda. here we describe ... | 1999 | 10400569 |
| surface proteins of gram-positive bacteria and mechanisms of their targeting to the cell wall envelope. | the cell wall envelope of gram-positive bacteria is a macromolecular, exoskeletal organelle that is assembled and turned over at designated sites. the cell wall also functions as a surface organelle that allows gram-positive pathogens to interact with their environment, in particular the tissues of the infected host. all of these functions require that surface proteins and enzymes be properly targeted to the cell wall envelope. two basic mechanisms, cell wall sorting and targeting, have been ide ... | 1999 | 10066836 |
| structure of the regular surface layer of aquaspirillum serpens mw5. | the structure of the regular surface layer of aquaspirillum serpens mw5 has been investigated by electon microscopy supplemented by computer image processing and least-squares analysis. the layer has a ribbed appearance, both on the bacterium and in isolated, negatively stained fragments. however, detailed analysis indicated that the layer was composed of two hexagonal sheets having p6mm symmetry and a = 16 nm. one sheet was staggered by one half repeat along a (1,0) line of the p6nm lattice rel ... | 1982 | 7061396 |
| cell wall proteins of aquaspirillum serpens. | the triton x-100-insoluble wall fraction of aquaspirillum serpens vha contained three major proteins: the regularly structured (rs) superficial protein (molecular weight 140,000) and two peptidoglycan-associated proteins (molecular weights, 32,000 and 33,000). the molecular arrangement and interactions of the outer membrane and rs proteins were examined with the use of bifunctional cross-linking reagents. the peptidoglycan-associated and rs proteins were not readily cross-linked in either homo- ... | 1981 | 6787011 |
| defined medium for aquaspirillum serpens vhl effective in batch and continuous culture. | a defined medium for aquaspirillum serpens vhl allows the replacement of the complex media now in use. it was developed by batch culture methods but supports growth in continuous culture. a basal salts medium supplemented with l-aspartic acid, l-alanine, and l-glutamic acid provided the best growth (turbidity), as long as ammonium chloride was omitted. ammonium chloride caused either a lag or a reduction or a complete inhibition of the growth of a. serpens vhl on the above amino acids and other ... | 1980 | 6766700 |
| identification and characterization of novel surface proteins in lactobacillus johnsonii and lactobacillus gasseri. | we have identified and sequenced the genes encoding the aggregation-promoting factor (apf) protein from six different strains of lactobacillus johnsonii and lactobacillus gasseri. both species harbor two apf genes, apf1 and apf2, which are in the same orientation and encode proteins of 257 to 326 amino acids. multiple alignments of the deduced amino acid sequences of these apf genes demonstrate a very strong sequence conservation of all of the genes with the exception of their central regions. n ... | 2002 | 12450842 |
| asei, a restriction endonuclease from aquaspirillum serpens which recognizes 5'at--taat3'. | | 1988 | 3264065 |
| basal-body-associated disks are additional structural elements of the flagellar apparatus isolated from wolinella succinogenes. | the intact flagella of wolinella succinogenes, a gram-negative, anaerobic bacterium with a single polar flagellum, were obtained by an improved procedure, introduced recently by aizawa et al. (s.-j. aizawa, g. e. dean, c. j. jones, r. m. macnab, and s. yamaguchi, j. bacteriol. 161:836-849, 1985) for the flagellum of salmonella typhimurium. disks with a diameter of 130 +/- 30 nm, which were attached to the basal body of the isolated intact flagella, could be identified by electron microscopy as a ... | 1989 | 2708319 |
| pneumonia and meningitis caused by a new nonfermentative unknown gram-negative bacterium. | seven isolates of an unclassified bacterium resembling flavobacterium spp. were characterized by growth requirements, microscopic examination, biochemical characteristics, antimicrobial susceptibility tests, protein profile analysis, and serologic data. the unclassified isolates were differentiated from flavobacterium meningosepticum, flavobacterium odoratum, flavobacterium balustinum, flavobacterium strain iib, chromobacterium violaceum, aquaspirillum serpens, and pseudomonas spp. the bacterium ... | 1989 | 2504766 |
| effect of paracrystalline protein surface layers on predation by bdellovibrio bacteriovorus. | we determined that paracrystalline protein surface arrays (s layers) protected gram-negative eubacteria from predation by bdellovibrio bacteriovorus. aquaspirillum serpens vha and mw5 and aquaspirillum sinuosum were resistant to predation by b. bacteriovorus 6-5-s when fully covered by their s layers. the s layer of aeromonas salmonicida a449 protected the cells from predication by b. bacteriovorus 109j. a predacious, plaque-forming vibrio that lysed an s-layer- variant of caulobacter crescentus ... | 1991 | 2007549 |
| structural conservation of chemotaxis machinery across archaea and bacteria. | chemotaxis allows cells to sense and respond to their environment. in bacteria, stimuli are detected by arrays of chemoreceptors that relay the signal to a two-component regulatory system. these arrays take the form of highly stereotyped super-lattices comprising hexagonally packed trimers-of-receptor-dimers networked by rings of histidine kinase and coupling proteins. this structure is conserved across chemotactic bacteria, and between membrane-bound and cytoplasmic arrays, and gives rise to th ... | 2015 | 25581459 |
| transport of lipopolysaccharide across the cell envelope: the long road of discovery. | intracellular lipid transport is poorly understood. genetic studies to identify lipid-transport factors are complicated by the essentiality of many lipids, whereas biochemical and cell biology approaches aiming to determine localization and mechanisms of lipid transport are often challenged by the lack of adequate technology. here, we review the epic history of how different approaches, technological advances and ingenuity contributed to the recent discovery of a multi-protein pathway that trans ... | 2009 | 19633680 |
| retrospective on the early development of cryoelectron microscopy of macromolecules and a prospective on opportunities for the future. | methods for preserving specimen hydration in protein crystals were pursued in the early 1970s as a prerequisite for protein crystallography using an electron microscope. three laboratories approached this question from very different directions. one built a differentially pumped hydration chamber that could maintain the crystal in a liquid water environment, a second maintained hydration by rapidly freezing the protein crystal and examining it in a cold stage, and the third replaced the water of ... | 2008 | 18606231 |
| s-layers: principles and applications. | monomolecular arrays of protein or glycoprotein subunits forming surface layers (s-layers) are one of the most commonly observed prokaryotic cell envelope components. s-layers are generally the most abundantly expressed proteins, have been observed in species of nearly every taxonomical group of walled bacteria, and represent an almost universal feature of archaeal envelopes. the isoporous lattices completely covering the cell surface provide organisms with various selection advantages including ... | 2014 | 24483139 |
| s-layer proteins. | | 2000 | 10648507 |
| small-angle x-ray scattering for imaging of surface layers on intact bacteria in the native environment. | crystalline cell surface layers (s-layers) represent a natural two-dimensional (2d) protein self-assembly system with nanometer-scale periodicity that decorate many prokaryotic cells. here, we analyze the s-layer on intact bacterial cells of the gram-positive organism geobacillus stearothermophilus atcc 12980 and the gram-negative organism aquaspirillum serpens mw5 by small-angle x-ray scattering (saxs) and relate it to the structure obtained by transmission electron microscopy (tem) after plati ... | 2013 | 23504021 |
| attachment of diaminopimelic acid to bdelloplast peptidoglycan during intraperiplasmic growth of bdellovibrio bacteriovorus 109j. | an early event in the predatory lifestyle of bdellovibrio bacteriovorus 109j is the attachment of diaminopimelic acid (dap) to the peptidoglycan of its prey. attachment occurs over the first 60 min of the growth cycle and is mediated by an extracellular activity(s) produced by the bdellovibrio. some 40,000 dap residues are incorporated into the escherichia coli bdelloplast wall, amounting to ca. 2 to 3% of the total initial dap content of its prey cells. incorporation of dap occurs when e. coli, ... | 1984 | 6202674 |
| three-dimensional structure of the surface layer protein of aquaspirillum serpens vha determined by electron crystallography. | the three-dimensional structure of the protein which forms the s layer of aquaspirillum serpens strain vha has been determined by electron microscopy. structures have been reconstructed to a resolution of about 1.6 nm for single-layered specimens and about 4 nm for two-layered specimens. the structure, which has hexagonal symmetry, consists of a core in the shape of a cup, with six projections arising from the rim of the cup to join adjacent subunits at the threefold symmetry axes. the model is ... | 1986 | 3745114 |
| components of the regular surface array of aquaspirillum serpens mw5 and their assembly in vitro. | the two-layered regular surface array of aquaspirillum serpens mw5 was removed from cell envelopes and dissociated into subunits by treatment with 6 m urea. the surface components reassembled onto an outer membrane surface and self-assembled into planar sheets in vitro in the presence of ca2+ or sr2+. the two layers were removed sequentially from cell envelopes by a two-step extraction procedure involving initial treatment with a high-ph buffer to remove the outermost surface layer and subsequen ... | 1984 | 6693353 |