TY - JOUR. T1 - Characterization of the Escherichia coli O59 and O155 O-antigen gene clusters. T2 - The atypical wzx genes are evolutionary related. AU - Guo, Hongjie. AU - Kong, Qingke. AU - Cheng, Jiansong. AU - Wang, Lei. AU - Feng, Lu. PY - 2005/7/15. Y1 - 2005/7/15. N2 - O-antigens are highly polymorphic. The genes specifically involved in O-antigen synthesis are generally grouped together on the chromosome as a gene cluster. In Escherichia coli, the O-antigen gene clusters are characteristically located between the housekeeping genes galF and gnd. In this study, the O-antigen gene clusters of E. coli O59 and E. coli O155 were sequenced. The former was found to contain genes for GDP-mannose synthesis, glycosyltransferase genes and the O-antigen polymerase gene (wzy), while the latter contained only glycosyltransferase genes and wzy. O unit flippase genes (wzx) were found immediately downstream of the gnd gene, in the region between the gnd and hisI genes in these two strains. This atypical ...
The A. salmonicida A450 LPS O-antigen, encoded by the wbsalmo gene cluster, is exported through an ABC-2 transporter-dependent pathway. It represents the first example of an O-antigen LPS polysaccharide with three different monosaccharides in their repeating unit assembled by this pathway. Until now, only repeating units with one or two different monosaccharides have been described. Functional genomic analysis of this wbsalmo region is mostly in agreement with the LPS O-antigen structure of acetylated l-rhamnose (Rha), d-glucose (Glc), and 2-amino-2-deoxy-d-mannose (ManN). Between genes of the wbsalmo we found the genes responsible for the biosynthesis and assembly of the S-layer (named A-layer in these strains). Through comparative genomic analysis and in-frame deletions of some of the genes, we concluded that all the A. salmonicida typical and atypical strains, other than A. salmonicida subsp. pectinolytica strains, shared the same wbsalmo and presence of A-layer. A. salmonicida subsp. pectinolytica
TY - JOUR. T1 - A complete view of the genetic diversity of the Escherichia coli O-antigen biosynthesis gene cluster. AU - Iguchi, Atsushi. AU - Iyoda, Sunao. AU - Kikuchi, Taisei. AU - Ogura, Yoshitoshi. AU - Katsura, Keisuke. AU - Ohnishi, Makoto. AU - Hayashi, Tetsuya. AU - Thomson, Nicholas R.. PY - 2015/1/1. Y1 - 2015/1/1. N2 - The O antigen constitutes the outermost part of the lipopolysaccharide layer in Gram-negative bacteria. The chemical composition and structure of the O antigen show high levels of variation even within a single species revealing itself as serological diversity. Here, we present a complete sequence set for the O-antigen biosynthesis gene clusters (O-AGCs) from all 184 recognized Escherichia coli O serogroups. By comparing these sequences, we identified 161 well-defined O-AGCs. Based on the wzx/wzy or wzm/wzt gene sequences, in addition to 145 singletons, 37 serogroups were placed into 16 groups. Furthermore, phylogenetic analysis of all the E. coli O-serogroup ...
2.A.66.2 The Polysaccharide Transport (PST) Family. The protein members of the PST family are generally of 400-500 amino acyl residues in size and traverse the membrane as putative α-helical spanners twelve times. Analyses conducted in 1997 showed that they formed two major clusters. One is concerned with lipopolysaccharide O-antigen (undecaprenol pyrophosphate-linked O-antigen repeat unit) export (flipping from the cytoplasmic side to the periplasmic side of the inner membranes) in Gram-negative bacteria. On the periplasmic side, polymerization occurs catalyzed by Wzy. The other is concerned with exopolysaccharide or capsular polysaccharide export in both Gram-negative and Gram-positive bacteria. However, arachaeal and eukaryotic homologues are now recognized. The mechanism of energy coupling is not established, but homology with the MATE family suggests that they are secondary carriers. A review of Wzx undecaprenyl pyrophosphate (UndPP)-linked polysaccharide repeat units occurs by a ...
Prior, JL; Parkhill, J; Hitchen, PG; Mungall, KL; Stevens, K; Morris, HR; Reason, AJ; Oyston, PCF; Dell, A; Wren, BW; +1 more... (2001) The failure of different strains of Yersinia pestis to produce lipopolysaccharide O-antigen under different growth conditions is due to mutations in the O-antigen gene cluster. FEMS microbiology letters, 197 (2). pp. 229-33. ISSN 0378-1097 Full text not available from this repository ...
Carbohydrates constitute one of the three major classes of biomolecules found in all living cells and, unlike nucleic acids and proteins, their polymeric structures are not based on a template. The structural diversity of these molecules confers them an enormous capacity to encode information in biological systems, acting as efficient mediators in the interaction of the cell with the environment. In order to understand the roles of glycans in biological processes it is of key importance to have a detailed understanding of their structures and conformational preferences, and NMR spectroscopy is one of most powerful techniques for the study of these molecules in solution.. This thesis is focused on the structural and conformational analysis of lipopolysaccharides from Gram-negative bacteria. In the first two projects (Chapter 2 and 3) the structural analyses of the biological repeating units of the O-antigen polysaccharides from E. coli O174ab and O115 are described; in both cases a combination of ...
Carbohydrates constitute one of the three major classes of biomolecules found in all living cells and, unlike nucleic acids and proteins, their polymeric structures are not based on a template. The structural diversity of these molecules confers them an enormous capacity to encode information in biological systems, acting as efficient mediators in the interaction of the cell with the environment. In order to understand the roles of glycans in biological processes it is of key importance to have a detailed understanding of their structures and conformational preferences, and NMR spectroscopy is one of most powerful techniques for the study of these molecules in solution.. This thesis is focused on the structural and conformational analysis of lipopolysaccharides from Gram-negative bacteria. In the first two projects (Chapter 2 and 3) the structural analyses of the biological repeating units of the O-antigen polysaccharides from E. coli O174ab and O115 are described; in both cases a combination of ...
Salmonella O Antigen Group D (Typhi O). Rapid Labs stained febrile antigen suspensions can be used to identify and quantitate specific antibodies in human sera following infection with certain Salmonellae pathogens. These febrile antigens are suitable for both the rapid slide and tube agglutination tests against human sera for the detection of these agglutinins.. These antigen suspensions are killed bacteria, stained to enhance the reading of agglutination tests. The blue stained antigens are specific to the somatic 0 antigens whilst the red stained antigens are specific to the flagellar H antigens.. Available in 5ml vials or bulk sizes.. ...
The biogenesis of the outer membrane requires that the individual components are transported from the site of synthesis to their final destination outside the inner membrane by crossing both hydrophilic and hydrophobic compartments. The machinery and the energy source that drive this process are not yet fully understood. The lipid A-core moiety and the O-antigen repeat units are synthesized at the cytoplasmic face of the inner membrane and are separately exported via two independent transport systems, namely, the O-antigen transporter Wzx (RfbX) and the ATP binding cassette (ABC) transporter MsbA that flips the lipid A-core moiety from the inner leaflet to the outer leaflet of the inner membrane.[2][3][4][5][6] O-antigen repeat units are then polymerised in the periplasm by the Wzy polymerase and ligated to the lipid A-core moiety by the WaaL ligase.[7][8] The LPS transport machinery is composed of LptA, LptB, LptC, LptD, LptE. This supported by the fact that depletion of any one of these ...
perosamine synthetase: a dual function enzyme that converts CDP-paratose to CPP-tyvelose; also converts GDP-4-keto-6-deoxymannose to perosamine
Two polysaccharides were isolated from Escherichia coli O12, the major being identified as the O12-antigen and the minor as the K5-antigen. The polysaccharides were studied by sugar analysis, Smith degradation, and one- and two-dimensional 1H and 13C NMR spectroscopy. As a result, the following structure of the O12-polysaccharide was elucidated, which, to our knowledge, has not been hitherto found in bacterial carbohydrates: →2)-β-d-Glcp-(1→6)-α-d-GlcpNAc-(1→3)-α-l-FucpNAc-(1→3)-β-d-GlcpNAc-(1→. The →4)-β-d-GlcpA-(1→4)-α-d-GlcpNAc-(1→ structure established for the K5-polysaccharide (heparosan) is previously known. Functions of genes in the O-antigen biosynthesis gene cluster of E. coli O12 were assigned by comparison with sequences in the available databases and found to be consistent with the O12-polysaccharide structure ...
Antigen O, polisaharid O ali stranska veriga O je ponavljajoči se glikanski polimer. Pripet je na oligosaharid sredice in predstavlja najbolj zunanji del molekule LPS. Sestava antigena O se razlikuje od bakterijskega seva do seva. Na primer samo pri različnih sevih bakterije E. coli obstaja več kot 160 različkov antigena O.[3] Prisotnost ali odsotnost antigena O odloča o tem, ali je lipopolisaharid opredeljen kot hrapav ali gladek. Verige antigena O s celotno dolžino napravijo lipopolisaharide gladke, če je antigen O odsoten ali skrajšan, pa govorimo o hrapavih LPS.[4] Bakterije s hrapavimi lipopolisaharidi so praviloma bolj prepustne za hidrofobne antibiotike, saj so hrapavi LPS bolj hidrofobni.[5] Antigen O je izpostavljen kot najbolj zunanji del bakterijske celice in zato predstavlja tarčo za gostiteljeva protitelesa. ...
Colnaghi, M I.; Pierotti, M A.; and Porta, G D., "Humoral and cellular immune responses recognizing different antigens on murine lymphosarcomas. Abstr." (1976). Subject Strain Bibliography 1976. 1320 ...
Expression of Y. pestis O-antigen reduces pathogen dissemination and host death. (a) KIM6+ and KIM6+-O+ (O-antigen expressing) were inoculated in mice following
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Identification of the specific O serogroup(s) responsible for the positive STEC result and verifies that all targets relevant to the definition of a Top 6 STEC (eae, stx and O group) are present within a single ...
Citation: Fratamico, P.M., Debroy, C., Miyamoto, T., Liu, Y. 2005. Detection of Enterohemorrhagic Escherichia Coli 0145 by PCR Targeting Genes in the E. Coli 0145 Antigen Gene Cluster and the Shiga Toxin 1 and Shiga Toxin 2 Genes. Association of Official Analytical Chemists. Abstract. Paper # P-611. Interpretive Summary: Technical Abstract: Enterohemorrhagic Escherichia coli serogroup O145 is an important cause of hemorrhagic colitis and hemolytic uremic syndrome worldwide. Cattle and other animals are potential reservoirs for this pathogen. To develop PCR assays for detection and identification of E. coli O145, the DNA sequence of the O antigen gene cluster of this E. coli serogroup was determined, and 15 open reading frames were identified. The wzx (O antigen flippase) and wzy (O antigen polymerase) genes in the O145 O antigen gene cluster were selected as targets for development of PCR assays specific for this serogroup. In addition, a multiplex PCR assay targeting the E. coli O145 wzx and ...
The O antigen of the Shigella flexneri lipopolysaccharide (LPS) is an important virulence determinant and immunogen. We have isolated S. flexneri mutants which produce a semi-rough LPS by using an O-antigen-specific phage, Sf6c. Western immunoblotting was used to show that the LPS produced by the semi-rough mutants contained only one O-antigen repeat unit. Thus, the mutants are deficient in production of the O-antigen polymerase and were termed rfc mutants. Complementation experiments were used to locate the rfc adjacent to the rfb genes on plasmid clones previously isolated and containing this region (D. F. Macpherson, R. Morona, D. W. Beger, K.-C. Cheah, and P. A. Manning, Mol. Microbiol 5:1491-1499, 1991). A combination of deletions and subcloning analysis located the rfc gene as spanning a 2-kb region. Insertion of a kanamycin resistance cartridge into a SalI site in this region inactivated the rfc gene. The DNA sequence of the rfc region was determined. An open reading frame spanning the ...
All organisms synthesize amidosugars, such as N-acetylglucosamine (GlcNAc), and deoxysugars, such as fucose. They are found in important polysaccharides and glycoconjugates such as glycoproteins. N-acetylquinovosamine (QuiNAc) is both an amido- and a deoxy-sugar. It is found in many examples of an important prokaryotic glycoconjugate, the lipopolysaccharide (LPS) that coats the surface of Gram-negative bacteria. Like N-glycosylation of glycoproteins, LPS has a portion that is synthesized first on a polyprenyl lipid carrier and then transferred to the rest of the molecule. QuiNAc is believed to initiate the O-antigen portion of LPS of Rhizobium etli CE3. Genetic studies identified three genes, wreV, wreU and wreQ, required for the initial steps of O-antigen synthesis in R. etli CE3. Based on the predicted roles of the gene products and the theory of polysaccharide biosynthesis, there was a very straightforward prediction of the initial events: WreV catalyzes conversion of UDP-GlcNAc to its 4-keto-6-deoxy
PubMedID: 23350972 | Laboratory adapted Escherichia coli K-12 becomes a pathogen of Caenorhabditis elegans upon restoration of O antigen biosynthesis. | Molecular microbiology | 3/1/2013
We have analyzed the O-antigen polysaccharide of the previously uncharacterized Escherichia coli strain TD2158 which is a host of bacteriophage HK620. This bacteriophage recognizes and cleaves the polysaccharide with its tailspike protein (TSP). The polysaccharide preparation as well as oligosaccharides obtained from HK620TSP endoglycosidase digests were analyzed with NMR spectroscopy. Additionally, sugar analysis was performed on the O-antigen polysaccharide and MALDI-TOF MS was used in oligosaccharide analysis. The present study revealed a heterogeneous polysaccharide with a hexasaccharide repeating unit of the following structure: alpha-D-Glcp-(1 -, 6) vertical bar vertical bar 2)-alpha-L-Rhap-(1 -, 6)-alpha-D-Glcp-(1 -, 4)-alpha-D-Galp-(1 -, 3)-alpha-D-GlcpNAc- (1 -,vertical bar beta-D-Glcp/beta-D-GlcpNAc-(1 -, 3) A repeating unit with a D-GlcNAc substitution of D-Gal has been described earlier as characteristic for serogroup O18A1. Accordingly, we termed repeating units with D-Glc ...
Four hydrophobic amino acids (Leu, Tyr, Phe, Trp) were oligomerized by the protease papain in homo-oligomerization, binary co-oligomerization and ternary co-oligomerization. After 24 h, solid polydisperse reaction products of the homo-oligomerization were obtained in yields ranging from 30-80% by weight. A DPavg was calculated based on MALDI-ToF MS results using the ion counts for the chains in the product. Based on the DPavg and the yield of the homo-oligomerization it was determined that the amino acids can be ranked according to reactivity in the order: Tyr | Leu | Phe | Trp. Thermal degradation of the homo-oligomers shows two degradation steps: at 178-239 °C and at 300-330 °C. All the products left a significant amount of char ranging from 18-57% by weight at 800 °C. Binary co-oligomers were obtained as a polydisperse precipitate with a compositional distribution of the chains. Both the compositional and chain length distribution are calculated from MALDI-ToF mass spectra. By comparing the amount
Ray, S. K., Rajeshwari, R., Shar ma, Y., and Sonti, R. V. 2002. A high-molecular-weight outer membrane protein of Xanthomonas oryzae pv. oryzae exhibits similarity to nonfimbrial adhesins of animal pathogeni c bacteria and is required for optimum virulence. Mol. Microbiol. 46:637-647. Regu, M., Enfedaque, J., Camprubi, S., and Toms, J. M. 1992. The O-antigen lipopolysaccharide is the major barrier to plasmid DNA uptake by Klebsiella pneumoniae during transformation by electroporation and os motic shock. J. Microbiol. Methods 15:129-134. Reinhold-Hurek, B., Maes, T., Gemmer, S., Van Montagu, M., and Hurek, T. 2006. An endoglucanase is involved in infection of rice roots by the not-cellulose-metabolizing endophyte Azoarcus sp strain BH72. Mol. Plan t-Microbe Interact. 19:181-188. Reiter, B., Brgmann, H., Burg, K., and Sessitsch, A. 2003. Endophytic nifH gene diversity in African sweet potato. Can. J. Microbiol. 49:549-555. Reslewic, S., Zhou, S., Place, M., Zhang, Y. P., Briska, A., Goldstein, S., ...
Małgorzata Czerwicka , Kinga Marszewska , Stephen J. Forsythe , Anna Bychowska , Alicja Mazgajczyk , Halina Dziadziuszko , Karolina Ossowska , Piotr Stepnowski , Zbigniew Kaczyński ...
Broeker, N. K.; Roske, Y.; Valleriani, A.; Stephan, M. S.; Andres, D.; Koetz, J.; Heinemann, U.; Barbirz, S.: Time-resolved DNA release from an O-antigen-specific Salmonella bacteriophage with a contractile tail. Journal of Biological Chemistry 294 (31), S. 11751 - 11761 (2019 ...
Authors: Pöschl, J.M.B. , Ruef, P. , Schnauffer, M. , Linderkamp, O. Article Type: Research Article Abstract: Lipopolysaccharide (LPS) of grant-negative bacteria consists of O-specific polysaccharide chain, core oligosaccharide chain and lipid A. Studies on the effect of various endotoxins on red blood cell (RBC) deformability gave conflicting results. To evaluate whether the effect of endotoxin on RBC deformability depends on the presence and exposure of lipid A, we studied the effect of five E.coli LPS components on RBC deformation by means of a shear stress diffractometer: 1) complete E.coli 0111:B4 LPS; 2) delipidated E.coli 0111 B4 LPS; 3) R-mutant E.coli F-583 LPS lacking the O-specific polysaccharide chain; 4) E.coli F-583 lipid A, and 5) electrodialysed E.coli …F-515 lipid A. Electrodialysis results in highly dispersed molecules whereas unelectrodialysed LPS tends to form aggregates. At a shear stress of 6 Pa RBC deformation was not changed by complete and delipidated LPS, but RBC ...
Once infection is established and bacterial levels increase, P. aeruginosa must evade adaptive immunity. Within the CF lung major changes in the phenotype of P. aeruginosa occur. These result in the overproduction of the cell surface polysaccharide alginate, loss of the LPS O antigen (Campodónico et al., 2008), and accumulation of DNA mutations caused by mutations affecting the DNA repair enzyme MutS (Oliver and Mena, 2010). Thus, the organism presents an ever-changing set of antigens for adaptive host immune responses. As CF patients do not have known defects in adaptive immunity, why cant they mount an effective immune response to clear P. aeruginosa? Some do, as it was shown almost 25 yr ago that a small subset of CF patients ,12 yr old remained uninfected and had serum antibodies that recognize alginate and facilitate opsonic killing (Pier et al., 1987). This antibody is not found in other CF patients or even in healthy humans, most of whom produce natural nonopsonic/nonprotective ...
Inner membrane protein YiaH; Involved in enterobacterial common antigen biosynthesis; catalyzes the addition of O-acetyl groups to the N-acetyl-D-glucosamine residues of the trisaccharide repeat units of the enterobacterial common antigen; Derived by automated computational analysis using gene prediction method- Protein Homology (331 aa ...
A structural study was performed by 13C-n.m.r. spectroscopy and methylation analysis of the O-chain of lipopolysaccharide (LPS) from Vibrio bioserogroup 1875 possessing antigenic factor(s) in common with O1 Vibrio cholerae. It was demonstrated to contain a linear homopolymer of (1→2)-linked N-3-hydroxypropionyl-alpha-D-perosamine [4-(3-hydroxypropanamido)-4,6-dideoxy-alpha-D-mannopyranose], which is very similar to, but not identical with, both (1→2)-linked linear N-3-deoxy-L-glycero-tetronyl(S-2,4-dihydroxybutyryl)-alpha-D - perosamine homopolymer and (1→2)-linked linear N-acetyl-alpha-D-perosamine homopolymer which constitute the O-chains of O1 V. cholerae and non-O1 V. cholerae bioserogroup Hakata LPS respectively. ...
Laser-micropyrolysis gas chromatography-mass spectrometry (La-Py-GC-MS) allows the analysis of small targeted areas of organic material. In this proof of concept study a novel application of the technique is demonstrated. Three types of organic matter preserved in speleothems were analysed: dissolved organic matter within the calcite crystal matrix; detrital organic inclusions; and lithified guano derived from birds and bats. The results indicate that there is significant heterogeneity within each sample type, with guano samples having the highest variability. However, there are also distinctive La-Py-GC-MS products that allow separation of the sample types geochemically. These include the chain length distribution within the longer chain n-alkanes (,C20), with the guano sample having a dominance of chain lengths below C27, whilst the other two sample types are dominated by n-alkanes of C27 and above. The detrital inclusion sample has a higher relative abundance of pyrrole and methylpyrroles. A ...
POLYSACCHARIDE STRUCTURE. References. Tombs, M .P. & Harding, S.E., An Introduction to Pol ysaccharide Biotechnology, Taylor & Francis, London, 1997 D.A. Rees, Polysaccharide Shapes, Chapman & Hall, 1977 Slideshow 198522 by johana
* found in: Polyvalent Antiserum: Serovar Inaba and Ogawa, Salmonella O 13 Antiserum, Salmonella O 2 Antiserum, Salmonella Polyvalent O Antiserum,..
Structures of the O-antigens of Klebsiella serotypes 02(2a, 2e), 02 (2a, 2e, 2h), and 02 (2a, 2f, 2g), members of a family of related D -galactan O-antigens in Klebsiella spp: Endotoxin Res.
As it is known that A group contained in its serum component which react with B antibody while the B group contained in its serum component that react with A antigen.. This serum component is known as antisera.. A -- Anti B --B group. B --Anti A --A group. These sera are available in market.. The antisera made from the human serum is called polyclonal antisera.. Now a days due to HIV disease scientist has discovered the synthetic sera which is known as monoclonal antisera.. In forensic the analysis of blood grouping from the crime exhibits is very important. For the analysis of blood from cloth the small portion of the blood cutting must be taken. But to analyze blood grouping from soil or weapon the thread must be prepared from the exhibits.. Preparation of Thread: -. The clean cotton thread is put in normal saline (the concentration of normal saline is 85% sodium chloride).. The wet thread is rubbed on weapon gently or on the soil particle and dry in the oven at 70 degree Celsius for 1-2 ...
Lipid-containing polysaccharides which are endotoxins and important group-specific antigens. They are often derived from the cell wall of gram-negative bacteria and induce immunoglobulin secretion. The lipopolysaccharide molecule consists of three parts: LIPID A, core polysaccharide, and O-specific chains (O ANTIGENS). When derived from Escherichia coli, lipopolysaccharides serve as polyclonal B-cell mitogens commonly used in laboratory immunology. (From Dorland, 28th ed ...
We have determined the sequence of the gene cluster encoding the O antigen in Francisella novicida and compared it to the previously reported O-antigen cluster in Francisella tularensis subsp. tularensis. Immunization with purified lipopolysaccharide (LPS) from F. tularensis subsp. tularensis or F. novicida protected against challenge with Francisella tularensis subsp. holarctica and F. novicida, respectively. The LPS from F. tularensis subsp. tularensis did not confer protection against challenge with F. novicida, and the LPS from F. novicida did not confer protection against challenge with F. tularensis subsp. holarctica. Allelic replacement mutants of F. tularensis subsp. tularensis or F. novicida which failed to produce O antigen were attenuated, but exposure to these mutants did not induce a protective immune response. The O antigen of F. tularensis subsp. tularensis appeared to be important for intracellular survival whereas the O antigen of F. novicida appeared to be critical for serum ...
Structures of the antigenic O-polysaccharides of lipopolysaccharides produced by Actinobacillus actinomycetemcomitans serotypes a, c, d and e
Shigella flexneri is the major pathogen causing bacillary dysentery. Fifteen serotypes have been recognized up to now. The genesis of new S. flexneri serotypes is commonly mediated by serotype-converting bacteriophages. Untypeable or novel serotypes from natural infections had been reported worldwide but have not been generated in laboratory. A new S. flexneri serotype-serotype 1 d was generated when a S. flexneri serotype Y strain (native LPS) was sequentially infected with 2 serotype-converting bacteriophages, SfX first and then SfI. The new serotype 1 d strain agglutinated with both serotype X-specific anti-7;8 grouping serum and serotype 1a-specific anti- I typing serum, and differed from subserotypes 1a, 1b and 1c. Twenty four S. flexneri clinical isolates of serotype X were all converted to serotype 1 d by infection with phage SfI. PCR and sequencing revealed that SfI and SfX were integrated in tandem into the proA-yaiC region of the host chromosome. These findings suggest a new S. flexneri
Functional analysis of genes responsible for the synthesis of the B-band O antigen of Pseudomonas aeruginosa serotype O6 lipopolysaccharide Academic Article ...
article{94637ed4-e20b-42af-8d9d-bc94eeba13cc, abstract = {,p,Synthesis of the hexasaccharide repeating unit of the O-antigen from E. coli O133 has been accomplished with rational protecting group manipulations on commercially available monosaccharides and stereoselective glycosylations through a convergent protocol. A late stage TEMPO mediated oxidation is used to install the required uronic acid moiety. Chloroacetate group is used extensively as a temporary protecting group.,/p,}, author = {Mitra, Ankita and Mukhopadhyay, Balaram}, issn = {1434-193X}, language = {eng}, month = {08}, number = {30}, pages = {4869--4878}, publisher = {John Wiley & Sons}, series = {European Journal of Organic Chemistry}, title = {Convergent Synthesis of the Hexasaccharide Repeating Unit of the O-Antigenic OPS of Escherichia coli O133}, url = {http://dx.doi.org/10.1002/ejoc.201900815}, doi = {10.1002/ejoc.201900815}, volume = {2019}, year = {2019 ...
Lipopolysaccharide (LPS) is the major component of the outer membrane of Gram-negative bacteria consisting of three domains: a hydrophobic anchor called lipid A, a non-repeating core oligosaccharide (OS) and a repetitive glycan polymer called O-antigen or O-polysaccharide (O-PS). The enzymes for the biosynthesis of lipid A are well conserved among Gram-negative bacterial species [MD:M00060 M00866]. The core OS connecting lipid A with O-antigen is divided into inner and outer parts. Five core types, K-12 and R1-R4, are identified in Escherichia coli, with the common inner part composed of Kdo (ketodeoxyoctulosonic acid) and Hep (heptose) residues and the outer part made of various sugar residues. O-antigen is the most variable part used for serotyping of pathogenic Escherichia coli, where about 170 types are known. All three domains are involved in toxicity, pathogenicity, antimicrobial resistance and other activities ...
SWISS-MODEL Repository entry for A1JID9 (UGPE_YERE8), sn-glycerol-3-phosphate transport system permease protein UgpE. Yersinia enterocolitica serotype O:8 / biotype 1B (strain NCTC 13174 /8081)
SWISS-MODEL Repository entry for A1JLA4 (DNLJ_YERE8), DNA ligase. Yersinia enterocolitica serotype O:8 / biotype 1B (strain NCTC 13174 /8081)
Ethylene polymers having a) a Polydispersity Index of about 2 to about 4; b) a melt index, MI, and Relaxation Spectrum Index, RSI, such that (RSI)(MI.sup.0.6) is about 2.5 to about 6.5; c) a Crystallizable Chain Length Distribution Index, L.sub.w /L.sub.n, of about 1.0 to about 9; and d) a density, .rho., and a percent haze when fabricated into films such that the percent haze is less than 370.rho.-330, are provided. These ethylene polymers advantageously combine superior clarity and toughness with low extractables and enhanced processing ease.
المجلة العراقية للعلوم Iraqi Journal of Science A Refereed Science Journal Issued by the College of Science University of Baghdad Baghdad-Iraq. مجلة علمية محكمة تصدرها كلية العلوم- جامعة بغداد، بغداد- جمهورية العراق EISSN: 2312-1637 ISSN: 0067-2904
Pseudomonas aeruginosa (o bacil piociànic, bacil del pus blau, bacil del pus verd) és un bacteri comú que causa malalties en animals i plantes, incloent-hi els humans. Es troba als sòls, aigua, flora de la pell, i molts ambients humans de tot el món. Ha colonitzat molts ambients naturals i artificials, ja que aquest bacteri pot viure no només en atmosferes normals sinó també en atmosferes hipòxiques. Com aliment fa servir un gran rang de materials orgànics, la seva versatilitat el permet infectar teixits danyats o persones amb el sistema immunitari reduït. Els símptomes de les infeccions són inflamació generalitzada i sèpsia. Si afecten òrgans com el pulmó, el tracte urinari i els ronyons el resultat pot ser fatal.[1] Com que prospera en moltes superfícies també es pot trobar aquest bacteri en lequipament mèdic, incloent-hi catèters, causant infeccions encreuades en hospitals i clíniques. També pot descompondre hidrocarburs i sha usat en la indústria petroliera.[2][3] ...
В Средиземноморской зоне, включая Эгейское море, в оставшихся географических районах и на внутренних территориях осадки уменьшаться. Температура воздуха увеличиться. Это означает, что сельское хозяйство и другие виды экономической деятельности, к которым мы привыкли, вынуждены претерпеть структурные изменения. Эти изменения наиболее затронут сферу туризма и сельского хозяйства. В итоге эти изменения будут носить отрицательный характер, вот что я имею в виду. В других областях, таких как Мармара, Фракия, Чёрное море, и возможно на востоке ...
Identification of the methyl phosphate substituent at the non-reducing terminal mannose residue of the O-specific polysaccharides of Klebsiella pneumoniae O3, Hafnia alvei PCM 1223 and Escherichia coli O9/O9a LPS
Accepted name: dTDP-4-amino-4,6-dideoxy-D-glucose acyltransferase. Reaction: acetyl-CoA + dTDP-4-amino-4,6-dideoxy-α-D-glucose = CoA + dTDP-4-acetamido-4,6-dideoxy-α-D-glucose. Other name(s): VioB. Systematic name: acetyl-CoA:dTDP-4-amino-4,6-dideoxy-α-D-glucose N-acetyltransferase. Comments: The non-activated product, 4-acetamido-4,6-dideoxy-α-D-glucose, is part of the O antigens of Shigella dysenteriae type 7 and Escherichia coli O7.. References:. 1. Wang, Y., Xu, Y., Perepelov, A.V., Qi, Y., Knirel, Y.A., Wang, L. and Feng, L. Biochemical characterization of dTDP-D-Qui4N and dTDP-D-Qui4NAc biosynthetic pathways in Shigella dysenteriae type 7 and Escherichia coli O7. J. Bacteriol. 189 (2007) 8626-8635. [PMID: 17905981]. ...
Although there has been much written about the phenotype of rough mutants, those reports have relied upon the characterization of fortuitous rough isolates. Since nothing was known about the genetic defects in those organisms, any biological properties attributed to the lack of O antigen influenced the interpretation of subsequent experimental observations. For example, Brucella ovis andB. canis are naturally occurring rough species which are pathogenic in their preferred hosts and resistant to complement-mediated lysis (10, 46). As a result, most researchers have maintained that these organisms must express a shortened (somehow undetectable) O antigen (43). However, recent work in our laboratory with the broadly reactive anti-lipid A antibody (MAb 177) described in this paper indicates the presence of LPS in B. ovis and B. canis which is indistinguishable from that observed in the lps mutants (CA353, CA533, and CA613) of B. abortus (data not shown). The differences in phenotype (virulent versus ...