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Selection of Salmonella enterica serovar Typhi genes involved during interaction with human macrophages by screening of a transposon mutant library. PLoS One 2012; 7:e36643. [PMID: 22574205 PMCID: PMC3344905 DOI: 10.1371/journal.pone.0036643] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 04/04/2012] [Indexed: 12/21/2022] Open
Abstract
The human-adapted Salmonella enterica serovar Typhi (S. Typhi) causes a systemic infection known as typhoid fever. This disease relies on the ability of the bacterium to survive within macrophages. In order to identify genes involved during interaction with macrophages, a pool of approximately 105 transposon mutants of S. Typhi was subjected to three serial passages of 24 hours through human macrophages. Mutants recovered from infected macrophages (output) were compared to the initial pool (input) and those significantly underrepresented resulted in the identification of 130 genes encoding for cell membrane components, fimbriae, flagella, regulatory processes, pathogenesis, and many genes of unknown function. Defined deletions in 28 genes or gene clusters were created and mutants were evaluated in competitive and individual infection assays for uptake and intracellular survival during interaction with human macrophages. Overall, 26 mutants had defects in the competitive assay and 14 mutants had defects in the individual assay. Twelve mutants had defects in both assays, including acrA, exbDB, flhCD, fliC, gppA, mlc, pgtE, typA, waaQGP, SPI-4, STY1867-68, and STY2346. The complementation of several mutants by expression of plasmid-borne wild-type genes or gene clusters reversed defects, confirming that the phenotypic impairments within macrophages were gene-specific. In this study, 35 novel phenotypes of either uptake or intracellular survival in macrophages were associated with Salmonella genes. Moreover, these results reveal several genes encoding molecular mechanisms not previously known to be involved in systemic infection by human-adapted typhoidal Salmonella that will need to be elucidated.
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Houppert AS, Kwiatkowski E, Glass EM, DeBord KL, Merritt PM, Schneewind O, Marketon MM. Identification of chromosomal genes in Yersinia pestis that influence type III secretion and delivery of Yops into target cells. PLoS One 2012; 7:e34039. [PMID: 22479512 PMCID: PMC3316589 DOI: 10.1371/journal.pone.0034039] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 02/21/2012] [Indexed: 01/05/2023] Open
Abstract
Pathogenic Yersinia species possess a type III secretion system, which is required for the delivery of effector Yop proteins into target cells during infection. Genes encoding the type III secretion machinery, its substrates, and several regulatory proteins all reside on a 70-Kb virulence plasmid. Genes encoded in the chromosome of yersiniae are thought to play important roles in bacterial perception of host environments and in the coordinated activation of the type III secretion pathway. Here, we investigate the contribution of chromosomal genes to the complex regulatory process controlling type III secretion in Yersinia pestis. Using transposon mutagenesis, we identified five chromosomal genes required for expression or secretion of Yops in laboratory media. Four out of the five chromosomal mutants were defective to various extents at injecting Yops into tissue culture cells. Interestingly, we found one mutant that was not able to secrete in vitro but was fully competent for injecting Yops into host cells, suggesting independent mechanisms for activation of the secretion apparatus. When tested in a mouse model of plague disease, three mutants were avirulent, whereas two strains were severely attenuated. Together these results demonstrate the importance of Y. pestis chromosomal genes in the proper function of type III secretion and in the pathogenesis of plague.
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Affiliation(s)
- Andrew S. Houppert
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Elizabeth Kwiatkowski
- Department of Microbiology, University of Chicago, Chicago, Illinois, United States of America
| | - Elizabeth M. Glass
- Mathematics and Computer Science Division, Argonne National Laboratory, Argonne, Illinois, United States of America
| | - Kristin L. DeBord
- Department of Microbiology, University of Chicago, Chicago, Illinois, United States of America
| | - Peter M. Merritt
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Olaf Schneewind
- Department of Microbiology, University of Chicago, Chicago, Illinois, United States of America
| | - Melanie M. Marketon
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
- Department of Microbiology, University of Chicago, Chicago, Illinois, United States of America
- * E-mail:
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53
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Hsieh PF, Lin TL, Yang FL, Wu MC, Pan YJ, Wu SH, Wang JT. Lipopolysaccharide O1 antigen contributes to the virulence in Klebsiella pneumoniae causing pyogenic liver abscess. PLoS One 2012; 7:e33155. [PMID: 22427976 PMCID: PMC3299736 DOI: 10.1371/journal.pone.0033155] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Accepted: 02/10/2012] [Indexed: 12/17/2022] Open
Abstract
Klebsiella pneumoniae is the common cause of a global emerging infectious disease, community-acquired pyogenic liver abscess (PLA). Capsular polysaccharide (CPS) and lipopolysaccharide (LPS) are critical for this microorganism's ability to spread through the blood and to cause sepsis. While CPS type K1 is an important virulence factor in K. pneumoniae causing PLA, the role of LPS in PLA is not clear. Here, we characterize the role of LPS O antigen in the pathogenesis of K. pneumoniae causing PLA. NTUH-K2044 is a LPS O1 clinical strain; the presence of the O antigen was shown via the presence of 1,3-galactan in the LPS, and of sequences that align with the wb gene cluster, known to produce O-antigen. Serologic analysis of K. pneumoniae clinical isolates demonstrated that the O1 serotype was more prevalent in PLA strains than that in non-tissue-invasive strains (38/42 vs. 9/32, P<0.0001). O1 serotype isolates had a higher frequency of serum resistance, and mutation of the O1 antigen changed serum resistance in K. pneumoniae. A PLA-causing strain of CPS capsular type K2 and LPS serotype O1 (i.e., O1:K2 PLA strain) deleted for the O1 synthesizing genes was profoundly attenuated in virulence, as demonstrated in separate mouse models of septicemia and liver abscess. Immunization of mice with the K2044 magA-mutant (K(1) (-) O(1)) against LPS O1 provided protection against infection with an O1:K2 PLA strain, but not against infection with an O1:K1 PLA strain. Our findings indicate that the O1 antigen of PLA-associated K. pneumoniae contributes to virulence by conveying resistance to serum killing, promoting bacterial dissemination to and colonization of internal organs after the onset of bacteremia, and could be a useful vaccine candidate against infection by an O1:K2 PLA strain.
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Affiliation(s)
- Pei-Fang Hsieh
- Department of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Tzu-Lung Lin
- Department of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Feng-Ling Yang
- The Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Meng-Chuan Wu
- Department of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Yi-Jiun Pan
- Department of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Shih-Hsiung Wu
- The Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Jin-Town Wang
- Department of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- * E-mail:
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54
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Ovchinnikova OG, Liu B, Guo D, Kocharova NA, Shashkov AS, Chen M, Feng L, Rozalski A, Knirel YA, Wang L. Localization and molecular characterization of putative O antigen gene clusters of Providencia species. MICROBIOLOGY-SGM 2012; 158:1024-1036. [PMID: 22282517 DOI: 10.1099/mic.0.055210-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Enterobacteria of the genus Providencia are opportunistic human pathogens associated with urinary tract and wound infections, as well as enteric diseases. The lipopolysaccharide (LPS) O antigen confers major antigenic variability upon the cell surface and is used for serotyping of Gram-negative bacteria. Recently, Providencia O antigen structures have been extensively studied, but no data on the location and organization of the O antigen gene cluster have been reported. In this study, the four Providencia genome sequences available were analysed, and the putative O antigen gene cluster was identified in the polymorphic locus between the cpxA and yibK genes. This finding provided the necessary information for designing primers, and cloning and sequencing the O antigen gene clusters from five more Providencia alcalifaciens strains. The gene functions predicted in silico were in agreement with the known O antigen structures; furthermore, annotation of the genes involved in the three-step synthesis of GDP-colitose (gmd, colD and colC) was supported by cloning and biochemical characterization of the corresponding enzymes. In one strain (P. alcalifaciens O39), no polysaccharide product of the gene cluster in the cpxA-yibK locus was found, and hence genes for synthesis of the existing O antigen are located elsewhere in the genome. In addition to the putative O antigen synthesis genes, homologues of wza, wzb, wzc and (in three strains) wzi, required for the surface expression of capsular polysaccharides, were found upstream of yibK in all species except Providencia rustigianii, suggesting that the LPS of these species may be attributed to the so-called K LPS (K(LPS)). The data obtained open a way for development of a PCR-based typing method for identification of Providencia isolates.
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Affiliation(s)
- Olga G Ovchinnikova
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russia.,TEDA School of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, 300457 Tianjin, PR China
| | - Bin Liu
- TEDA School of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, 300457 Tianjin, PR China
| | - Dan Guo
- TEDA School of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, 300457 Tianjin, PR China
| | - Nina A Kocharova
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russia
| | - Alexander S Shashkov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russia
| | - Miao Chen
- TEDA School of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, 300457 Tianjin, PR China
| | - Lu Feng
- Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, 23 Hongda Street, TEDA, 300457 Tianjin, PR China.,TEDA School of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, 300457 Tianjin, PR China
| | - Antoni Rozalski
- Department of Immunobiology of Bacteria, Institute of Microbiology, Biotechnology and Immunology, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland
| | - Yuriy A Knirel
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russia
| | - Lei Wang
- Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, 23 Hongda Street, TEDA, 300457 Tianjin, PR China.,TEDA School of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, 300457 Tianjin, PR China
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55
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Czyzyk DJ, Liu C, Taylor EA. Lipopolysaccharide biosynthesis without the lipids: recognition promiscuity of Escherichia coli heptosyltransferase I. Biochemistry 2011; 50:10570-2. [PMID: 22059588 DOI: 10.1021/bi201581b] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heptosyltransferase I (HepI) is responsible for the transfer of l-glycero-d-manno-heptose to a 3-deoxy-α-D-oct-2-ulopyranosonic acid (Kdo) of the growing core region of lipopolysaccharide (LPS). The catalytic efficiency of HepI with the fully deacylated analogue of Escherichia coli HepI LipidA is 12-fold greater than with the fully acylated substrate, with a k(cat)/K(m) of 2.7 × 10(6) M(-1) s(-1), compared to a value of 2.2 × 10(5) M(-1) s(-1) for the Kdo(2)-LipidA substrate. Not only is this is the first demonstration that an LPS biosynthetic enzyme is catalytically enhanced by the absence of lipids, this result has significant implications for downstream enzymes that are now thought to utilize deacylated substrates.
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Affiliation(s)
- Daniel J Czyzyk
- Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
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56
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Gourlay LJ, Sommaruga S, Nardini M, Sperandeo P, Dehò G, Polissi A, Bolognesi M. Probing the active site of the sugar isomerase domain from E. coli arabinose-5-phosphate isomerase via X-ray crystallography. Protein Sci 2011; 19:2430-9. [PMID: 20954237 DOI: 10.1002/pro.525] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Lipopolysaccharide (LPS) biosynthesis represents an underexploited target pathway for novel antimicrobial development to combat the emergence of multidrug-resistant bacteria. A key player in LPS synthesis is the enzyme D-arabinose-5-phosphate isomerase (API), which catalyzes the reversible isomerization of D-ribulose-5-phosphate to D-arabinose-5-phosphate, a precursor of 3-deoxy-D-manno-octulosonate that is an essential residue of the LPS inner core. API is composed of two main domains: an N-terminal sugar isomerase domain (SIS) and a pair of cystathionine-β-synthase domains of unknown function. As the three-dimensional structure of an enzyme is a prerequisite for the rational development of novel inhibitors, we present here the crystal structure of the SIS domain of a catalytic mutant (K59A) of E. coli D-arabinose-5-phosphate isomerase at 2.6-Å resolution. Our structural analyses and comparisons made with other SIS domains highlight several potentially important active site residues. In particular, the crystal structure allowed us to identify a previously unpredicted His residue (H88) located at the mouth of the active site cavity as a possible catalytic residue. On the basis of such structural data, subsequently supported by biochemical and mutational experiments, we confirm the catalytic role of H88, which appears to be a generally conserved residue among two-domain isomerases.
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Affiliation(s)
- Louise J Gourlay
- Dipartimento di Scienze Biomolecolari e Biotecnologie, and CIMAINA, Università di Milano, Via Celoria 26, Milano 20133, Italy
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57
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Airoldi C, Sommaruga S, Merlo S, Sperandeo P, Cipolla L, Polissi A, Nicotra F. Targeting Bacterial Membranes: Identification of Pseudomonas aeruginosaD-Arabinose-5P Isomerase and NMR Characterisation of its Substrate Recognition and Binding Properties. Chembiochem 2011; 12:719-27. [DOI: 10.1002/cbic.201000754] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Indexed: 11/10/2022]
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58
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Bae HB, Jeong CW, Li M, Kim HS, Kwak SH. Effects of Urinary Trypsin Inhibitor on Lipopolysaccharide-Induced Acute Lung Injury in Rabbits. Inflammation 2011; 35:176-82. [DOI: 10.1007/s10753-011-9303-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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59
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Abstract
Endotoxin refers lipopolysaccharide that constitutes the outer leaflet of the outer membrane of most Gram-negative bacteria. Lipopolysaccharide is comprised of a hydrophilic polysaccharide and a hydrophobic component known as lipid A which is responsible for the major bioactivity of endotoxin. Lipopolysaccharide can be recognized by immune cells as a pathogen-associated molecule through Toll-like receptor 4. Most enzymes and genes related to the biosynthesis and export of lipopolysaccharide have been identified in Escherichia coli, and they are shared by most Gram-negative bacteria based on available genetic information. However, the detailed structure of lipopolysaccharide differs from one bacterium to another, suggesting that additional enzymes that can modify the basic structure of lipopolysaccharide exist in bacteria, especially some pathogens. These structural modifications of lipopolysaccharide are sometimes tightly regulated. They are not required for survival but closely related to the virulence of bacteria. In this chapter we will focus on the mechanism of biosynthesis and export of lipopolysaccharide in bacteria.
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Affiliation(s)
- Xiaoyuan Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.
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60
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Bae HB, Li M, Son JK, Seo CS, Chung SH, Kim SJ, Jeong CW, Lee HG, Kim W, Park HC, Kwak SH. Sauchinone, a lignan from Saururus chinensis, reduces tumor necrosis factor-α production through the inhibition of c-raf/MEK1/2/ERK 1/2 pathway activation. Int Immunopharmacol 2010; 10:1022-8. [DOI: 10.1016/j.intimp.2010.06.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 05/07/2010] [Accepted: 06/01/2010] [Indexed: 10/19/2022]
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61
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Fedonenko IP, Katsy EI, Petrova LP, Boĭko AS, Zdorovenko EL, Kachala VV, Shashkov AS, Knirel' IA. [The structure of the O-specific polysaccharide from a mutant of nitrogen-fixing rhizobacterium Azospirillum brasilense Sp245 with an altered plasmid content]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2010; 36:236-40. [PMID: 20531482 DOI: 10.1134/s1068162010020111] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The rhizobacteria Azospirillum brasilense Sp245 produce antigenically different lipopolysaccharides LPSI and LPSII, both containing identical pentasaccharides built from D-rhamnose residues as the repeated chains of O-specific oligosaccharides (OPS). In this study, we report the structure of the OPS from A. brasilense LPSI(-)LPSII(-)-mutant Sp245.5, which spontaneously lost the p85 and p120 plasmids upon the formation of a new 300-MDa megaplasmid after the long-term storage of the bacteria in a rich medium. The repeating unit of the A. brasilense mutant Sp245.5 appeared to be a disaccharide consisting of residues of N-acetyl-D-galactosamine and N-acetyl-D-mannosaminuronic acid: [Formula: see text].
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Affiliation(s)
- Iu P Fedonenko
- Institute of Biochemistry and Physiology of Plants, Russian Academy of Sciences, pr. Entuziastov 13, Saratov, 410049 Russia.
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Katsy EI, Petrova LP, Kulibyakina OV, Prilipov AG. Analysis of Azospirillum brasilense plasmid loci coding for (Lipo)polysaccharides synthesis enzymes. Microbiology (Reading) 2010. [DOI: 10.1134/s002626171002013x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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63
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Eilers B, Mayer-Scholl A, Walker T, Tang C, Weinrauch Y, Zychlinsky A. Neutrophil antimicrobial proteins enhance Shigella flexneri adhesion and invasion. Cell Microbiol 2010; 12:1134-43. [PMID: 20331641 DOI: 10.1111/j.1462-5822.2010.01459.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Shigella flexneri is an enteric pathogen that causes massive inflammation and destruction of the human intestinal epithelium. Neutrophils are the first cells of the innate immune system recruited to the site of infection. These cells can attack microbes by phagocytosis, Neutrophil Extracellular Trap (NET) formation and degranulation. Here, we investigated how neutrophil degranulation affects virulence and show that exposure of Shigella to granular proteins enhances infection of epithelial cells. During this process, cationic granular proteins bind to the Shigella surface causing increased adhesion which ultimately leads to hyperinvasion. This effect is mediated by changes in the surface charge, since a lipopolysaccharide (LPS) mutant with a negative surface shows enhanced hyperinvasion compared with wild-type Shigella. We propose that Shigella evolved to use host defence molecules to enhance its virulence and subvert the innate immune system.
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Affiliation(s)
- Björn Eilers
- Department of Cellular Microbiology, Max-Planck-Institute for Infection Biology, Berlin, Germany
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64
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Airoldi C, Sommaruga S, Merlo S, Sperandeo P, Cipolla L, Polissi A, Nicotra F. Targeting Bacterial Membranes: NMR Spectroscopy Characterization of Substrate Recognition and Binding Requirements of D-Arabinose-5-Phosphate Isomerase. Chemistry 2010; 16:1897-902. [DOI: 10.1002/chem.200902619] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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65
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Kojima H, Inagaki M, Tomita T, Watanabe T. Diversity of non-stoichiometric substitutions on the lipopolysaccharide of E. coli C demonstrated by electrospray ionization single quadrupole mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2010; 24:43-48. [PMID: 19957294 DOI: 10.1002/rcm.4355] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The lipopolysaccharide (LPS) of enterobacteria frequently contains various numbers of charged non-stoichiometric substituents such as phosphate (P) and ethanolamine (EtN) groups and a third residue of 3-deoxy-D-manno-2-octulosonic acid (KDO) on the R-core polysaccharide backbone. These substituents can modify the biological activities of LPS including varying the stability of the outer membrane, tolerance to cationic antibiotics, pathogenicity, and sensitivity to enterobacteria bacteriophages. These diverse substituents can be clearly detected in degraded samples of LPS from E. coli C using electrospray ionization single quadrupole mass spectrometry (ESI-Q-MS) from a 0.1 mg/mL solution in a 50:50 mixture of methanol and 10 mM ammonium acetate (pH 6.8). The O-deacylated derivative showed multiple peaks of [M-3H](3-) ions which corresponded to species having up to eight phosphates, two ethanolamines, and an additional KDO on the backbone of Hex(5) Hep(3) KDO(2) GlcN(2) C14:0(3-OH)(2). The major components of the O,N-deacylated derivative were the species associated with four and five phosphates on Hex(5) Hep(3) KDO(2) GlcN(2). The polysaccharide portion of LPS also revealed species which corresponded to Hex(5) Hep(3) KDO associated with two to four phosphates and an ethanolamine. The present method was proved to be useful to investigate the structural diversity of enterobacterial LPS.
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Affiliation(s)
- Hisaki Kojima
- Analytical Science, Pre-Clinical Development, Banyu Pharmaceutical Co. Ltd., 3 Okubo, Tsukuba, Ibaraki, 300-2611, Japan
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66
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The Effect of Epigallocatechin Gallate on Lipopolysaccharide-Induced Acute Lung Injury in a Murine Model. Inflammation 2009; 33:82-91. [DOI: 10.1007/s10753-009-9161-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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67
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Lipopolysaccharide: Biosynthetic pathway and structure modification. Prog Lipid Res 2009; 49:97-107. [PMID: 19815028 DOI: 10.1016/j.plipres.2009.06.002] [Citation(s) in RCA: 287] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 06/16/2009] [Accepted: 06/17/2009] [Indexed: 01/13/2023]
Abstract
Lipopolysaccharide that constitutes the outer leaflet of the outer membrane of most Gram-negative bacteria is referred to as an endotoxin. It is comprised of a hydrophilic polysaccharide and a hydrophobic component referred to as lipid A. Lipid A is responsible for the major bioactivity of endotoxin, and is recognized by immune cells as a pathogen-associated molecule. Most enzymes and genes coding for proteins responsible for the biosynthesis and export of lipopolysaccharide in Escherichia coli have been identified, and they are shared by most Gram-negative bacteria based on genetic information. The detailed structure of lipopolysaccharide differs from one bacterium to another, consistent with the recent discovery of additional enzymes and gene products that can modify the basic structure of lipopolysaccharide in some bacteria, especially pathogens. These modifications are not required for survival, but are tightly regulated in the cell and closely related to the virulence of bacteria. In this review we discuss recent studies of the biosynthesis and export of lipopolysaccharide, and the relationship between the structure of lipopolysaccharide and the virulence of bacteria.
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68
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Madaeni SS, Zarbakhsh M. Removal of organics and ions from wastewater using a hybrid system of microfiltration membrane and microorganisms. Eng Life Sci 2009. [DOI: 10.1002/elsc.200800094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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69
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Sharma O, Datsenko KA, Ess SC, Zhalnina MV, Wanner BL, Cramer WA. Genome-wide screens: novel mechanisms in colicin import and cytotoxicity. Mol Microbiol 2009; 73:571-85. [PMID: 19650773 DOI: 10.1111/j.1365-2958.2009.06788.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Only two new genes (fkpA and lepB) have been identified to be required for colicin cytotoxicity in the last 25 years. Genome-wide screening using the 'Keio collection' to test sensitivity to colicins (col) A, B, D, E1, E2, E3, E7 and N from groups A and B, allowed identification of novel genes affecting cytotoxicity and provided new information on mechanisms of action. The requirement of lipopolysaccharide for colN cytotoxicity resides specifically in the lipopolysaccharide inner-core and first glucose. ColA cytotoxicity is dependent on gmhB and rffT genes, which function in the biosynthesis of lipopolysaccharide and enterobacterial common antigen. Of the tol genes that function in the cytoplasmic membrane translocon, colE1 requires tolA and tolR but not tolQ for activity. Peptidoglycan-associated lipoprotein, which interacts with the Tol network, is not required for cytotoxicity of group A colicins. Except for TolQRA, no cytoplasmic membrane protein is essential for cytotoxicity of group A colicins, implying that TolQRA provides the sole pathway for their insertion into/through the cytoplasmic membrane. The periplasmic protease that cleaves between the receptor and catalytic domains of colE7 was not identified, implying either that the responsible gene is essential for cell viability, or that more than one gene product has the necessary proteolysis function.
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Affiliation(s)
- Onkar Sharma
- Department of Biological Sciences, Lilly Hall of Life Sciences, Purdue University, West Lafayette, IN 47907, USA
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70
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Abstract
Many bioactive compounds contain as part of their molecules one or more deoxysugar units. Their presence in the final compound is generally necessary for biological activity. These sugars derive from common monosaccharides, like d-glucose, which have lost one or more hydroxyl groups (monodeoxysugars, dideoxysugars, trideoxysugars) during their biosynthesis. These deoxysugars are transferred to the final molecule by the action of a glycosyltransferase. Here, we first summarize the different biosynthetic steps required for the generation of the different families of deoxysugars, including those containing extra methyl or amino groups, or tailoring modifications of the glycosylated compounds. We then give examples of several strategies for modification of the glycosylation pattern of a given bioactive compound: inactivation of genes involved in the biosynthesis of deoxysugars; heterologous expression of genes for the biosynthesis or transfer of a specific deoxysugar; and combinatorial biosynthesis (including the use of gene cassette plasmids). Finally, we report techniques for the isolation and detection of the new glycosylated derivatives generated using these strategies.
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Affiliation(s)
- Felipe Lombó
- Departamento de Biología Funcional and Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, Oviedo, Spain
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Rotman E, Bratcher P, Kuzminov A. Reduced lipopolysaccharide phosphorylation in Escherichia coli lowers the elevated ori/ter ratio in seqA mutants. Mol Microbiol 2009; 72:1273-92. [PMID: 19432803 DOI: 10.1111/j.1365-2958.2009.06725.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The seqA defect in Escherichia coli increases the ori/ter ratio and causes chromosomal fragmentation, making seqA mutants dependent on recombinational repair (the seqA recA colethality). To understand the nature of this chromosomal fragmentation, we characterized DeltaseqA mutants and isolated suppressors of the DeltaseqA recA lethality. We demonstrate that our DeltaseqA alleles have normal function of the downstream pgm gene and normal ratios of the major phospholipids in the membranes, but increased surface lipopolysaccharide (LPS) phosphorylation. The predominant class of DeltaseqA recA suppressors disrupts the rfaQGP genes, reducing phosphorylation of the inner core region of LPS. The rfaQGP suppressors also reduce the elevated ori/ter ratio of the DeltaseqA mutants but, unexpectedly, the suppressed mutants still exhibit the high levels of chromosomal fragmentation and SOS induction, characteristic of the DeltaseqA mutants. We also found that colethality of rfaP with defects in the production of acidic phospholipids is suppressed by alternative initiation of chromosomal replication, suggesting that LPS phosphorylation stimulates replication initiation. The rfaQGP suppression of the seqA recA lethality provides genetic support for the surprising physical evidence that the oriC DNA forms complexes with the outer membrane.
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Affiliation(s)
- Ella Rotman
- Department of Microbiology, University of Illinois, Urbana-Champaign, IL, USA
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72
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Su J, Timbely D, Zhu M, Hua X, Liu B, Pang Y, Shen H, Qi J, Yang Y. RfaB, a galactosyltransferase, contributes to the resistance to detergent and the virulence of Salmonella enterica serovar Enteritidis. Med Microbiol Immunol 2009; 198:185-94. [PMID: 19404677 DOI: 10.1007/s00430-009-0115-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Indexed: 12/27/2022]
Abstract
In this study, a deletion mutant of rfaB (DeltarfaB) was observed to be susceptible to sodium dodecyl sulfate and less tolerant to bile salts. In addition, pre-incubation in 10% bile salts increased bacterial tolerance to 30% bile salts. We also showed that the DeltarfaB mutant invaded HeLa cells less than the wild type and resulted in a lower ratio of intracellular bacteria. Competitive infection of mice showed that the DeltarfaB mutant was defective in the colonization of host organs and was cleared more quickly in fecal shedding. Transforming of a plasmid containing a wild-type allele of rfaB (pRB3-rfaB) partially rescued the defect of the DeltarfaB mutant. The results suggest that RfaB, which is responsible to add the glycosyl residue to the core lipopolysaccharide, contributes to the tolerance to detergent and the virulence of Salmonella enterica serovar Enteritidis.
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Affiliation(s)
- Jing Su
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Institute of Virology, Nanjing University, Nanjing, People's Republic of China
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73
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Chart H, Daniel RMA, Cheasty T. The expression of lipopolysaccharide by strains of Shigella dysenteriae, Shigella flexneri and Shigella boydii and their cross-reacting strains of Escherichia coli. FEMS Microbiol Lett 2009; 292:21-6. [PMID: 19222579 DOI: 10.1111/j.1574-6968.2008.01466.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Strains of Shigella dysenteriae, Shigella flexneri and Shigella boydii express lipopolysaccharides, that enable the serotyping of strains based on their antigenic structures. Certain strains of S. dysenteriae, S. flexneri and S. boydii are known to share epitopes with strains of Escherichia coli; however, the lipopolysaccharide profiles of the cross-reacting organisms have not been compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) lipopolysaccharides profiling. In the present study, type strains of these bacteria were examined using SDS-PAGE/silver staining to compare their respective lipopolysaccharide profiles. Strains of S. dysenteriae, S. boydii and S. flexneri all expressed long-chain lipopolysaccharide, with distinct profile patterns. The majority of strains of Shigella spp., known to cross-react with strains of E. coli, had lipopolysaccharide profiles quite distinct from the respective strain of E. coli. It was concluded that while cross-reacting strains of Shigella spp. and E. coli may express shared lipopolysaccharide epitopes, their lipopolysaccharide structures are not identical.
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Affiliation(s)
- Henrik Chart
- Laboratory of Gastrointestinal Pathogens, Department of Gastrointestinal, Emerging and Zoonotic Infections, Centre for Infections, Health Protection Agency, London, UK.
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74
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Thibodeaux C, Melançon C, Liu HW. Biosynthese von Naturstoffzuckern und enzymatische Glycodiversifizierung. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200801204] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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75
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Holland AM, Rather PN. Evidence for extracellular control of RpoS proteolysis in Escherichia coli. FEMS Microbiol Lett 2008; 286:50-9. [PMID: 18616600 DOI: 10.1111/j.1574-6968.2008.01255.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The RpoS sigma factor is required for the transition of Escherichia coli into stationary phase, as well as adaptation to environmental stresses and nutrient depletion. In this study, we report that under nutrient poor conditions, RpoS protein accumulation in E. coli was strongly enhanced by a secreted factor. Expression of a single copy RpoS'-'LacZ translational fusion was activated 12-fold by the signal, but a single copy rpoS-lacZ transcriptional fusion was only activated 1.6-fold. The extracellular signal activated the RpoS'-'LacZ translational fusion in dsrA, rprA or dsrA/rprA mutant backgrounds, but did not activate in an hfq mutant background. A RpoS379'-'LacZ translational fusion, missing the region of RpoS required for the RssB (SprE)/ClpXP-dependent proteolysis, was not activated by the extracellular signal. Furthermore, in a rssB(sprE)::Tn10 background, the presence of extracellular signal did not significantly activate expression above the already elevated levels. Western and Northern blot analysis demonstrated that the extracellular signal significantly increased the levels of RpoS protein, but not mRNA. The extracellular signal did not bind to reversed-phase C-18 columns, was dialyzable, and stable to pH 2, pH 12 and heat. However, protease treatment drastically reduced signal activity. Extracellular signal activity was absent in an hldD (rfaD) mutant, but was present in cell lysates, suggesting that signal was unable to be exported in an hldD mutant.
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76
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Cunneen MM, Reeves PR. Membrane topology of theSalmonella entericaserovar Typhimurium Group B O-antigen translocase Wzx. FEMS Microbiol Lett 2008; 287:76-84. [DOI: 10.1111/j.1574-6968.2008.01295.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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77
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Gao S, Peng D, Zhang W, Muszyński A, Carlson RW, Gu XX. Identification of two late acyltransferase genes responsible for lipid A biosynthesis in Moraxella catarrhalis. FEBS J 2008; 275:5201-14. [PMID: 18795947 DOI: 10.1111/j.1742-4658.2008.06651.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Lipid A is a biological component of the lipo-oligosaccharide of a human pathogen, Moraxella catarrhalis. No other acyltransferases except for UDP-GlcNAc acyltransferase, responsible for lipid A biosynthesis in M. catarrhalis, have been identified. By bioinformatics, two late acyltransferase genes, lpxX and lpxL, responsible for lipid A biosynthesis were identified, and knockout mutants of each gene in M. catarrhalis strain O35E were constructed and named O35ElpxX and O35ElpxL. Structural analysis of lipid A from the parental strain and derived mutants showed that O35ElpxX lacked two decanoic acids (C10:0), whereas O35ElpxL lacked one dodecanoic (lauric) acid (C12:0), suggesting that lpxX encoded decanoyl transferase and lpxL encoded dodecanoyl transferase. Phenotypic analysis revealed that both mutants were similar to the parental strain in their toxicity in vitro. However, O35ElpxX was sensitive to the bactericidal activity of normal human serum and hydrophobic reagents. It had a reduced growth rate in broth and an accelerated bacterial clearance at 3 h (P < 0.01) or 6 h (P < 0.05) after an aerosol challenge in a murine model of bacterial pulmonary clearance. O35ElpxL presented similar patterns to those of the parental strain, except that it was slightly sensitive to the hydrophobic reagents. These results indicate that these two genes, particularly lpxX, encoding late acyltransferases responsible for incorporation of the acyloxyacyl-linked secondary acyl chains into lipid A, are important for the biological activities of M. catarrhalis.
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Affiliation(s)
- Song Gao
- Vaccine Research Section, National Institute on Deafness and Other Communication Disorders, Rockville, MD 20850, USA
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78
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Lukáčová M, Barák I, Kazár J. Role of structural variations of polysaccharide antigens in the pathogenicity of Gram-negative bacteria. Clin Microbiol Infect 2008; 14:200-6. [DOI: 10.1111/j.1469-0691.2007.01876.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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79
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Ho N, Kondakova AN, Knirel YA, Creuzenet C. The biosynthesis and biological role of 6-deoxyheptose in the lipopolysaccharide O-antigen of Yersinia pseudotuberculosis. Mol Microbiol 2008; 68:424-47. [DOI: 10.1111/j.1365-2958.2008.06163.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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80
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Vorhölter FJ, Schneiker S, Goesmann A, Krause L, Bekel T, Kaiser O, Linke B, Patschkowski T, Rückert C, Schmid J, Sidhu VK, Sieber V, Tauch A, Watt SA, Weisshaar B, Becker A, Niehaus K, Pühler A. The genome of Xanthomonas campestris pv. campestris B100 and its use for the reconstruction of metabolic pathways involved in xanthan biosynthesis. J Biotechnol 2008; 134:33-45. [PMID: 18304669 DOI: 10.1016/j.jbiotec.2007.12.013] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Revised: 12/04/2007] [Accepted: 12/24/2007] [Indexed: 10/22/2022]
Abstract
The complete genome sequence of the Xanthomonas campestris pv. campestris strain B100 was established. It consisted of a chromosome of 5,079,003bp, with 4471 protein-coding genes and 62 RNA genes. Comparative genomics showed that the genes required for the synthesis of xanthan and xanthan precursors were highly conserved among three sequenced X. campestris pv. campestris genomes, but differed noticeably when compared to the remaining four Xanthomonas genomes available. For the xanthan biosynthesis genes gumB and gumK earlier translational starts were proposed, while gumI and gumL turned out to be unique with no homologues beyond the Xanthomonas genomes sequenced. From the genomic data the biosynthesis pathways for the production of the exopolysaccharide xanthan could be elucidated. The first step of this process is the uptake of sugars serving as carbon and energy sources wherefore genes for 15 carbohydrate import systems could be identified. Metabolic pathways playing a role for xanthan biosynthesis could be deduced from the annotated genome. These reconstructed pathways concerned the storage and metabolization of the imported sugars. The recognized sugar utilization pathways included the Entner-Doudoroff and the pentose phosphate pathway as well as the Embden-Meyerhof pathway (glycolysis). The reconstruction indicated that the nucleotide sugar precursors for xanthan can be converted from intermediates of the pentose phosphate pathway, some of which are also intermediates of glycolysis or the Entner-Doudoroff pathway. Xanthan biosynthesis requires in particular the nucleotide sugars UDP-glucose, UDP-glucuronate, and GDP-mannose, from which xanthan repeat units are built under the control of the gum genes. The updated genome annotation data allowed reconsidering and refining the mechanistic model for xanthan biosynthesis.
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Affiliation(s)
- Frank-Jörg Vorhölter
- Universität Bielefeld, Biologie VI (Genetik), Universitätsstr. 25, D-33615 Bielefeld, Germany
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81
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Thibodeaux CJ, Melançon CE, Liu HW. Natural-product sugar biosynthesis and enzymatic glycodiversification. Angew Chem Int Ed Engl 2008; 47:9814-59. [PMID: 19058170 PMCID: PMC2796923 DOI: 10.1002/anie.200801204] [Citation(s) in RCA: 320] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Many biologically active small-molecule natural products produced by microorganisms derive their activities from sugar substituents. Changing the structures of these sugars can have a profound impact on the biological properties of the parent compounds. This realization has inspired attempts to derivatize the sugar moieties of these natural products through exploitation of the sugar biosynthetic machinery. This approach requires an understanding of the biosynthetic pathway of each target sugar and detailed mechanistic knowledge of the key enzymes. Scientists have begun to unravel the biosynthetic logic behind the assembly of many glycosylated natural products and have found that a core set of enzyme activities is mixed and matched to synthesize the diverse sugar structures observed in nature. Remarkably, many of these sugar biosynthetic enzymes and glycosyltransferases also exhibit relaxed substrate specificity. The promiscuity of these enzymes has prompted efforts to modify the sugar structures and alter the glycosylation patterns of natural products through metabolic pathway engineering and enzymatic glycodiversification. In applied biomedical research, these studies will enable the development of new glycosylation tools and generate novel glycoforms of secondary metabolites with useful biological activity.
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Affiliation(s)
- Christopher J. Thibodeaux
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX. (USA), 78712
| | - Charles E. Melançon
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX. (USA), 78712
| | - Hung-wen Liu
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX. (USA), 78712
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82
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Abstract
Glucose-1-phosphate uridylyltransferase, or UGPase, catalyzes the production of UDP-glucose from glucose-1-phosphate and UTP. Because of the biological role of UDP-glucose in glycogen synthesis and in the formation of glycolipids, glycoproteins, and proteoglycans, the enzyme is widespread in nature. Recently this laboratory reported the three-dimensional structure of UGPase from Escherichia coli. While the initial X-ray analysis revealed the overall fold of the enzyme, details concerning its active site geometry were limited because crystals of the protein complexed with either substrates or products could never be obtained. In an effort to more fully investigate the active site geometry of the enzyme, UGPase from Corynebacterium glutamicum was subsequently cloned and purified. Here we report the X-ray structure of UGPase crystallized in the presence of both magnesium and UDP-glucose. Residues involved in anchoring the ligand to the active site include the polypeptide chain backbone atoms of Ala 20, Gly 21, Gly 117, Gly 180, and Ala 214, and the side chains of Glu 36, Gln 112, Asp 143, Glu 201, and Lys 202. Two magnesium ions are observed coordinated to the UDP-glucose. An alpha- and a beta-phosphoryl oxygen, three waters, and the side chain of Asp 142 ligate the first magnesium, whereas the second ion is coordinated by an alpha-phosphoryl oxygen and five waters. The position of the first magnesium is conserved in both the glucose-1-phosphate thymidylyltransferases and the cytidylyltransferases. The structure presented here provides further support for the role of the conserved magnesium ion in the catalytic mechanisms of the sugar-1-phosphate nucleotidylyltransferases.
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Affiliation(s)
- James B Thoden
- Department of Biochemistry, University of Wisconsin, Madison 53706-1544, USA
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83
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Hodgson JC. Endotoxin and Mammalian Host Responses During Experimental Disease. J Comp Pathol 2006; 135:157-75. [PMID: 17101336 DOI: 10.1016/j.jcpa.2006.09.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2006] [Accepted: 09/04/2006] [Indexed: 10/23/2022]
Abstract
Endotoxin is an integral component of the outer membrane of Gram-negative bacteria and a prime example of unique and highly conserved bacterial surface molecules that engage with the innate immune system of the mammalian host via pattern recognition receptors on a range of host cells. The results of this interaction, which may be beneficial or detrimental to the development and welfare of the host, are reviewed, focusing on the different sensitivities and consequences in a range of hosts of experimental exposure to endotoxin, the disease outcomes and recent developments in our understanding of the mechanisms involved.
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Affiliation(s)
- J C Hodgson
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK.
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84
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Zhang P, Snyder S, Feng P, Azadi P, Zhang S, Bulgheresi S, Sanderson KE, He J, Klena J, Chen T. Role of N-acetylglucosamine within core lipopolysaccharide of several species of gram-negative bacteria in targeting the DC-SIGN (CD209). THE JOURNAL OF IMMUNOLOGY 2006; 177:4002-11. [PMID: 16951363 DOI: 10.4049/jimmunol.177.6.4002] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Our recent studies have shown that the dendritic cell-specific ICAM nonintegrin CD209 (DC-SIGN) specifically binds to the core LPS of Escherichia coli K12 (E. coli), promoting bacterial adherence and phagocytosis. In this current study, we attempted to map the sites within the core LPS that are directly involved in LPS-DC-SIGN interaction. We took advantage of four sets of well-defined core LPS mutants, which are derived from E. coli, Salmonella enterica serovar Typhimurium, Neisseria gonorrhoeae, and Haemophilus ducreyi and determined interaction of each of these four sets with DC-SIGN. Our results demonstrated that N-acetylglucosamine (GlcNAc) sugar residues within the core LPS in these bacteria play an essential role in targeting the DC-SIGN receptor. Our results also imply that DC-SIGN is an innate immune receptor and the interaction of bacterial core LPS and DC-SIGN may represent a primeval interaction between Gram-negative bacteria and host phagocytic cells.
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Affiliation(s)
- Pei Zhang
- Department of Biomedical Sciences, College of Medicine, University of Illinois at Chicago, Rockford, IL 61107, USA
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85
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Sperandeo P, Pozzi C, Dehò G, Polissi A. Non-essential KDO biosynthesis and new essential cell envelope biogenesis genes in the Escherichia coli yrbG–yhbG locus. Res Microbiol 2006; 157:547-58. [PMID: 16765569 DOI: 10.1016/j.resmic.2005.11.014] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2005] [Revised: 11/22/2005] [Accepted: 11/30/2005] [Indexed: 11/27/2022]
Abstract
In Escherichia coli and most Gram-negative bacteria, KDO (3-deoxy-D-manno-octulosonate), a component of the lipopolysaccharide inner core, is essential for outer membrane biogenesis and cell viability. Two recently identified genes involved in KDO biosynthesis, kdsD and kdsC, belong to the yrbG-yhbG locus where four additional ORFs (yrbG, yrbK, yhbN and yhbG) with unknown function are located. We have constructed six conditional expression mutants in which the arabinose-inducible araBp promoter is respectively located upstream of each gene of the locus. Complementation analysis of these mutants indicates that the locus is organized in at least three operons and that the three distal genes (yrbK, yhbN and yhbG) are essential for E. coli viability. Surprisingly, kdsD and kdsC (encoding a D-arabinose 5-phosphate isomerase and a KDO 8-phosphate phosphatase, respectively) were shown to be non-essential, indicating genetic redundancy for these two functions. A preliminary characterization of the arabinose-dependent mutants under permissive conditions and upon depletion revealed increased sensitivity to hydrophobic toxic chemicals, suggesting that the mutants have a defective outer membrane. These genes may thus be implicated in cell envelope integrity.
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Affiliation(s)
- Paola Sperandeo
- Dipartimento di Scienze biomolecolari e Biotecnologie, Università degli Studi di Milano, Milan, Italy
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86
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Zhang T, Wang L, Xu G, Chen Y, Zhang Y, Li Y. Disruption of ste23 gene affects composition profile and bioactivity of exopolysaccharide produced by Streptomyces sp. 139. Lett Appl Microbiol 2006; 42:132-7. [PMID: 16441377 DOI: 10.1111/j.1472-765x.2005.01810.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS To study the function of the gene ste23 involved in the biosynthesis of Ebosin. METHODS AND RESULTS In search of databases, the deduced product of the gene ste23 showed high homology to dTDP-4-dehydrorhamnose 3,5-epimerases. ste23 was replaced by a kanamycin resistance gene through double crossover. Compared with Ebosin, an exopolysaccharide (EPS) produced by wild-type Streptomyces sp. 139, the EPS produced by the ste23 mutant (designated EPS1) had a remarkably different monosaccharide composition and significantly diminished rhamnose content, though the molecular mass of EPS1 was similar to that of Ebosin. In addition, EPS1 lost the interleukin 1 (IL-1) antagonist activity in vitro. CONCLUSIONS ste23 may be involved in the Ebosin biosynthesis in S. sp. 139. and its bioactivity. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first genetic work investigating functions of genes involved in EPS production in streptomyces by gene replacement of the pathway genes.
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Affiliation(s)
- T Zhang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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87
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Mazur A, Marczak M, Król JE, Skorupska A. Topological and transcriptional analysis of pssL gene product: a putative Wzx-like exopolysaccharide translocase in Rhizobium leguminosarum bv. trifolii TA1. Arch Microbiol 2005; 184:1-10. [PMID: 16044265 DOI: 10.1007/s00203-005-0018-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2004] [Revised: 03/29/2005] [Accepted: 04/04/2005] [Indexed: 11/30/2022]
Abstract
An identified pssL gene is yet another one, besides the pssT, pssN and pssP genes, encoding for a protein engaged in polysaccharide polymerization and export in Rhizobium leguminosarum bv. trifolii strain TA1 (RtTA1). Amino acid sequence similarity and hypothetical protein secondary structure placed the PssL protein within Wzx (RfbX) translocases with putative flippase function that belong to the polysaccharide specific transport (PST) family. The predicted secondary structure of the PssL membrane protein was examined with a series of PssL-PhoA and PssL-LacZ translational fusions. The results support the hypothesis of PssL being a member of PST protein family comprising transporters with 12 membrane spanning segments and amino and carboxyl termini located in the cytoplasm. Results of semi-quantitative RT-PCR showed that the initial abundance of mRNA encoding PssL protein was relatively lower when compared to the quantity of the previously identified PssT membrane protein. PssL might be a good candidate for Wzx-like protein that together with PssT (Wzy protein) could be responsible for Wzx/Wzy-like-dependent EPS polymerization and translocation in RtTA1.
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Affiliation(s)
- Andrzej Mazur
- Department of General Microbiology, Institute of Microbiology and Biotechnology, University of M. Curie-Skłodowska, 19 Akademicka St., 20-033, Lublin, Poland.
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88
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Herlax V, de Alaniz MJT, Bakás L. Role of lipopolysaccharide on the structure and function of alpha-hemolysin from Escherichia coli. Chem Phys Lipids 2005; 135:107-15. [PMID: 15921972 DOI: 10.1016/j.chemphyslip.2005.02.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2004] [Revised: 02/01/2005] [Accepted: 02/07/2005] [Indexed: 11/23/2022]
Abstract
alpha-Hemolysin (HlyA) is a protein toxin (107 kDa) secreted by some pathogenic strains of E. coli. Several studies suggested the relationship between HlyA and lipopolysaccharide (LPS). We have studied experimentally the role of LPS on the stability and function of this toxin. The HlyA conformation in both, LPS-free and LPS-bound forms was investigated by tryptophan fluorescence. Studies about HlyA thermal and chemical denaturation indicated that its stability increased in the presence of LPS. On the other hand, the presence of negative and polar residues on the LPS reduced the tendency of HlyA to self-aggregation, and they may be the reservoir of calcium, cation essential for the lytic action of this toxin on red blood cells. These results suggest that HlyA and LPS are combined mainly via hydrophobic force to form an active toxin which stability is favored by the LPS.
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Affiliation(s)
- V Herlax
- Instituto de Investigaciones Bioquímicas La Plata, Facultad de Ciencias Médicas, 60 y 120, 1900 La Plata, Argentina
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89
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Abstract
Lipopolysaccharide (LPS) is the major surface molecule of Gram-negative bacteria and consists of three distinct structural domains: O-antigen, core, and lipid A. The lipid A (endotoxin) domain of LPS is a unique, glucosamine-based phospholipid that serves as the hydrophobic anchor of LPS and is the bioactive component of the molecule that is associated with Gram-negative septic shock. The structural genes encoding the enzymes required for the biosynthesis of Escherchia coli lipid A have been identified and characterized. Lipid A is often viewed as a constitutively synthesized structural molecule. However, determination of the exact chemical structures of lipid A from diverse Gram-negative bacteria shows that the molecule can be further modified in response to environmental stimuli. These modifications have been implicated in virulence of pathogenic Gram-negative bacteria and represent one of the molecular mechanisms of microbial surface remodeling used by bacteria to help evade the innate immune response. The intent of this review is to discuss the enzymatic machinery involved in the biosynthesis of lipid A, transport of the molecule, and finally, those enzymes involved in the modification of its structure in response to environmental stimuli.
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Affiliation(s)
- M Stephen Trent
- Department of Microbiology, East Tennessee State University, J.H. Quillen College of Medicine, Johnson City, 37164, USA.
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90
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Helander IM, Haikara A, Sadovskaya I, Vinogradov E, Salkinoja-Salonen MS. Lipopolysaccharides of anaerobic beer spoilage bacteria of the genusPectinatus– lipopolysaccharides of a Gram-positive genus. FEMS Microbiol Rev 2004; 28:543-52. [PMID: 15539073 DOI: 10.1016/j.femsre.2004.05.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2004] [Revised: 04/07/2004] [Accepted: 05/11/2004] [Indexed: 11/18/2022] Open
Abstract
Bacteria of the genus Pectinatus emerged during the seventies as contaminants and spoilage organisms in packaged beer. This genus comprises two species, Pectinatus cerevisiiphilus and Pectinatus frisingensis; both are strict anaerobes. On the basis of genomic properties the genus is placed among low GC Gram-positive bacteria (phylum Firmicutes, class Clostridia, order Clostridiales, family Acidaminococcaceae). Despite this assignment, Pectinatus bacteria possess an outer membrane and lipopolysaccharide (LPS) typical of Gram-negative bacteria. The present review compiles the structural and compositional studies performed on Pectinatus LPS. These lipopolysaccharides exhibit extensive heterogeneity, i.e. several macromolecularly and structurally distinct LPS molecules are produced by each strain. Whereas heterogeneity is a common property in lipopolysaccharides, Pectinatus LPS have been shown to contain exceptional carbohydrate structures, consisting of a fairly conserved core region that carries a large non-repetitive saccharide that probably replaces the O-specific chain. Such structures represent a novel architectural principle of the LPS molecule.
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Affiliation(s)
- Ilkka M Helander
- Division of Microbiology, Department of Applied Chemistry and Microbiology, University of Helsinki, Finland.
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91
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Markine-Goriaynoff N, Gillet L, Van Etten JL, Korres H, Verma N, Vanderplasschen A. Glycosyltransferases encoded by viruses. J Gen Virol 2004; 85:2741-2754. [PMID: 15448335 DOI: 10.1099/vir.0.80320-0] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Studies of cellular biology in recent decades have highlighted the crucial roles of glycans in numerous important biological processes, raising the concept of glycomics that is now considered as important as genomics, transcriptomics and proteomics. For millions of years, viruses have been co-evolving with their hosts. Consequently, during this co-evolution process, viruses have acquired mechanisms to mimic, hijack or sabotage host processes that favour their replication, including mechanisms to modify the glycome. The importance of the glycome in the regulation of host–virus interactions has recently led to a new concept called ‘glycovirology’. One fascinating aspect of glycovirology is the study of how viruses affect the glycome. Viruses reach that goal either by regulating expression of host glycosyltransferases or by expressing their own glycosyltransferases. This review describes all virally encoded glycosyltransferases and discusses their established or putative functions. The description of these enzymes illustrates several intriguing aspects of virology and provides further support for the importance of glycomics in biological processes.
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Affiliation(s)
- Nicolas Markine-Goriaynoff
- Immunology-Vaccinology (B43b), Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, B-4000 Liège, Belgium
| | - Laurent Gillet
- Immunology-Vaccinology (B43b), Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, B-4000 Liège, Belgium
| | - James L Van Etten
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska, Lincoln, NE 68583-0722, USA
| | - Haralambos Korres
- School of Biochemistry & Molecular Biology, Faculty of Science, Australian National University, Canberra, ACT 0200, Australia
| | - Naresh Verma
- School of Biochemistry & Molecular Biology, Faculty of Science, Australian National University, Canberra, ACT 0200, Australia
| | - Alain Vanderplasschen
- Immunology-Vaccinology (B43b), Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, B-4000 Liège, Belgium
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92
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Vorhölter FJ, Thias T, Meyer F, Bekel T, Kaiser O, Pühler A, Niehaus K. Comparison of two Xanthomonas campestris pathovar campestris genomes revealed differences in their gene composition. J Biotechnol 2004; 106:193-202. [PMID: 14651861 DOI: 10.1016/j.jbiotec.2003.08.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
For the Xanthomonas campestris pathovar campestris wild-type strain B100 a plasmid-based clone library was constructed. The plasmids carried chromosomal fragments of 3-4 kb in size that were tagged in vitro with the artificial transposon KAN-2. More than 3000 of the transposon target sites were characterized by DNA sequencing. The sequences obtained were compared to the recently published genome of Xanthomonas campestris pathovar campestris strain ATCC 33913. Most of the sequenced clones derived from strain B100 matched the chromosomal sequence of strain ATCC 33913. An alignment to the circular map of this chromosome revealed that the similarities were statistically distributed over the entire genome of strain ATCC 33913. The similarity was obvious for protein coding sequences, as well as for mobile genetic elements. However, four regions in the genome of Xanthomonas campestris pathovar campestris strain ATCC 33913, ranging in size from 11 to 37 kb, were not represented in the sequenced clone library of Xanthomonas campestris pathovar campestris strain B100. On the other hand, 1.2% of the sequenced clones originating from Xanthomonas campestris pathovar campestris strain B100 showed no or insignificant similarities to the genome of strain ATCC 33913.
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Affiliation(s)
- F-J Vorhölter
- Universität Bielefeld, Lehrstuhl für Genetik, POB 100131, 33501 Bielefeld, Germany
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93
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Novotny R, Schäffer C, Strauss J, Messner P. S-layer glycan-specific loci on the chromosome of Geobacillus stearothermophilus NRS 2004/3a and dTDP-L-rhamnose biosynthesis potential of G. stearothermophilus strains. MICROBIOLOGY-SGM 2004; 150:953-965. [PMID: 15073305 DOI: 10.1099/mic.0.26672-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The approximately 16.5 kb surface layer (S-layer) glycan biosynthesis (slg) gene cluster of the Gram-positive thermophile Geobacillus stearothermophilus NRS 2004/3a has been sequenced. The cluster is located immediately downstream of the S-layer structural gene sgsE and consists of 13 ORFs that have been identified by database sequence comparisons. The cluster encodes dTDP-L-rhamnose biosynthesis (rml operon), required for building up the polyrhamnan S-layer glycan, as well as for assembly and export of the elongated glycan chain, and its transfer to the S-layer protein. This is the first report of a gene cluster likely to be involved in the glycosylation of an S-layer protein. There is evidence that this cluster is transcribed as a polycistronic unit, whereas sgsE is transcribed monocistronically. To get insights into the regulatory mechanisms underlying glycosylation of the S-layer protein, the influence of growth temperature on the S-layer was investigated in seven closely related G. stearothermophilus strains, of which only strain NRS 2004/3a possessed a glycosylated S-layer. Chromosomal DNA preparations of these strains were screened for the presence of the rml operon, because L-rhamnose is a frequent constituent of S-layer glycans. From rml-positive strains, flanking regions of the operon were sequenced. Comparison with the slg gene cluster of G. stearothermophilus NRS 2004/3a revealed sequence homologies between adjacent genes. The temperature inducibility of S-layer protein glycosylation was investigated in those strains by raising the growth temperature from 55 degrees C to 67 degrees C; no change of either the protein banding pattern or the glycan staining behaviour was observed on SDS-PAGE gels, although the sgsE transcript was several-fold more abundant at 67 degrees C. Cell-free extracts of the strains were capable of converting dTDP-D-glucose to dtdp-L-rhamnose. Taken together, the results indicate that the rml locus is highly conserved among G. stearothermophilus strains, and that in the investigated rml-containing strains, dTDP-L-rhamnose is actively synthesized in vitro. However, in contrast to previous reports for G. stearothermophilus wild-type strains, an increase in growth temperature did not switch an S-layer protein phenotype to an S-layer glycoprotein phenotype, via the de novo generation of a new S-layer gene sequence.
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Affiliation(s)
- René Novotny
- Center for NanoBiotechnology, University of Applied Life Sciences and Natural Resources, A-1180 Wien, Austria
| | - Christina Schäffer
- Center for NanoBiotechnology, University of Applied Life Sciences and Natural Resources, A-1180 Wien, Austria
| | - Joseph Strauss
- Center of Applied Genetics, University of Applied Life Sciences and Natural Resources, A-1190 Wien, Austria
| | - Paul Messner
- Center for NanoBiotechnology, University of Applied Life Sciences and Natural Resources, A-1180 Wien, Austria
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94
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Bittner M, Saldías S, Altamirano F, Valvano MA, Contreras I. RpoS and RpoN are involved in the growth-dependent regulation of rfaH transcription and O antigen expression in Salmonella enterica serovar Typhi. Microb Pathog 2004; 36:19-24. [PMID: 14643636 DOI: 10.1016/j.micpath.2003.08.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We reported earlier that the production of O antigen lipopolysaccharide (LPS) by Salmonella enterica serovar Typhi (Salmonella typhi) increases at the onset of stationary phase and correlates with a growth-regulated expression of the rfaH gene under the control of the alternative sigma factor RpoN (Microbiology 148 (2002) 3789). In this study, we demonstrate that RpoS also modulates rfaH promoter activity as revealed by the absence of growth-dependent regulation of an rfaH-lacZ transcriptional fusion and O antigen production in a S. typhi rpoS mutant. Introduction of a constitutively expressed rpoN gene into the rpoS mutant restored increased production of O antigen during stationary phase, suggesting that constitutive production of RpoN could overcome the RpoS defect. Similar results were observed when an rpoS rpoN double mutant was transformed with the intact rpoN gene. Thus, we conclude that both RpoS and RpoN control the rfaH promoter activity and concomitantly, the production of O-specific LPS in S. typhi.
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Affiliation(s)
- Mauricio Bittner
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, P.O. Box 174 Correo 22, Santiago, Chile
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95
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Sirisena DM, Skurnik M. Mutations in the genes for synthesis of the outer core region of the lipopolysaccharide of Yersinia enterocolitica O:3. J Appl Microbiol 2003; 94:686-92. [PMID: 12631204 DOI: 10.1046/j.1365-2672.2003.01897.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS The aim of this study was to construct non-polar frame-shift mutations in some of the individual genes responsible for the biosynthesis of the branching outer core (OC) hexasaccharide of the lipopolysaccharide (LPS) in Yersinia enterocolitica O:3 (YeO:3). METHODS AND RESULTS Chromosomal segments of YeO:3 containing wbcN, wbcO and wbcQ genes were cloned into a suicide vector. A frame-shift mutation was introduced into each gene by modifying a unique restriction enzyme recognition site. Each recombinant plasmid with a modified OC gene was mobilized into YeO:3 to allow for allelic exchange between the modified gene and the wild type chromosomal gene. The exchange was confirmed by demonstrating the absence of the particular restriction site in the chromosome of each mutant strain. Analysis of LPS by gel electrophoresis showed that the LPS of the mutants was lacking the OC. Therefore, the constructed wbcN, wbcO and wbcQ strains are true mutants with frame-shifts in the corresponding genes. CONCLUSIONS The products of the wbcN, wbcO and wbcQ genes are putative glycosyltransferases and, based on the present analysis, essential for the biosynthesis of the OC hexasaccharide. The absence of OC in the LPS of these mutants further supports the hypothesis that the OC hexasaccharide is a single O-antigen O-unit that is not polymerized in YeO:3. SIGNIFICANCE AND IMPACT OF THE STUDY These mutants provide information on the unique nature of the synthesis of OC of YeO:3 LPS. They are valuable for future biochemical studies to establish the roles of the products of individual OC genes.
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Affiliation(s)
- D M Sirisena
- Department of Medical Biochemistry and Molecular Biology, Institute of Biomedicine, University of Turku, Finland.
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96
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Lawrence ML, Banes MM, Azadi P, Reeks BY. The Edwardsiella ictaluri O polysaccharide biosynthesis gene cluster and the role of O polysaccharide in resistance to normal catfish serum and catfish neutrophils. MICROBIOLOGY (READING, ENGLAND) 2003; 149:1409-1421. [PMID: 12777482 DOI: 10.1099/mic.0.26138-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Edwardsiella ictaluri, the causative agent of enteric septicaemia of catfish (ESC), expresses long O polysaccharide (OPS) chains on its surface. The authors previously reported the construction of an isogenic Ed. ictaluri OPS mutant strain and demonstrated that this strain is avirulent in channel catfish. This paper reports the cloning of the Ed. ictaluri OPS biosynthesis gene cluster and identification of the mutated gene in the OPS-negative strain. The sequenced region contains eight complete ORFs and one incomplete ORF encoding LPS biosynthesis enzymes. The mutated gene (designated wbiT) was similar to other bacterial galactose-4-epimerases. Glycosyl composition analysis indicated that wild-type Ed. ictaluri OPS contains higher amounts of galactose and N-acetylgalactosamine than the OPS mutant strain, which correlated well with predicted functions of the genes identified in the OPS biosynthesis cluster. The OPS mutant had a relatively small, but significant, decrease in its ability to survive in normal catfish serum compared to wild-type Ed. ictaluri, but it retained the ability to resist killing by catfish neutrophils.
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Affiliation(s)
- Mark L Lawrence
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762-6100, USA
| | - Michelle M Banes
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762-6100, USA
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, 220 Riverbend Road, Athens, GA 30602-4712, USA
| | - Brenda Y Reeks
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762-6100, USA
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97
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Host Immunity and Vaccine Development to Coccidia and Salmonella Infections in Chickens. J Poult Sci 2003. [DOI: 10.2141/jpsa.40.151] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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98
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Bittner M, Saldı As S, Estévez C, Zaldı Var M, Marolda CL, Valvano MA, Contreras I. O-antigen expression in Salmonella enterica serovar Typhi is regulated by nitrogen availability through RpoN-mediated transcriptional control of the rfaH gene. MICROBIOLOGY (READING, ENGLAND) 2002; 148:3789-3799. [PMID: 12480883 DOI: 10.1099/00221287-148-12-3789] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The authors previously reported increased expression of the Salmonella enterica serovar Typhi (S. typhi) rfaH gene when the bacterial cells reach stationary phase. In this study, using a lacZ fusion to the rfaH promoter region, they demonstrate that growth-dependent regulation of rfaH expression occurs at the level of transcription initiation. It was also observed that production of the lipopolysaccharide (LPS) O-antigen by S. typhi Ty2 correlated with the differential expression of rfaH during bacterial growth. This was probably due to the increased cellular levels of RfaH, since expression of the distal gene in the O-antigen gene cluster of S. typhi Ty2, wbaP, was also increased during stationary growth, as demonstrated by RT-PCR analysis. Examination of the sequences upstream of the rfaH coding region revealed homologies to potential binding sites for the RcsB/RcsA dimer of the RcsC/YopJ/RcsB phosphorelay regulatory system and for the RpoN alternative sigma factor. The expression of the rfaH gene in rpoN and rcsB mutants of S. typhi Ty2 was measured. The results indicate that inactivation of rpoN, but not of rcsB, suppresses the growth-phase-dependent induction of rfaH expression. Furthermore, production of beta-galactosidase mediated by the rfaH-lacZ fusion increased approximately fourfold when bacteria were grown in a nitrogen-limited medium. Nitrogen limitation was also shown to increase the expression of the O-antigen by the wild-type S. typhi Ty2, as demonstrated by a similar electrophoretic profile to that observed during the stationary phase of growth in rich media. It is therefore concluded that the relationship between LPS production and nitrogen limitation parallels the pattern of rfaH regulation under the control of RpoN and is consistent with the idea that RpoN modulates LPS formation via its effect on rfaH gene expression during bacterial growth.
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Affiliation(s)
- Mauricio Bittner
- Departamento de Bioquı́mica y Biologı́a Molecular, Facultad de Ciencias Quı́micas y Farmacéuticas, Universidad de Chile, PO Box 174, Correo 22, Santiago, Chile1
| | - Soledad Saldı As
- Departamento de Bioquı́mica y Biologı́a Molecular, Facultad de Ciencias Quı́micas y Farmacéuticas, Universidad de Chile, PO Box 174, Correo 22, Santiago, Chile1
| | - Claudia Estévez
- Departamento de Bioquı́mica y Biologı́a Molecular, Facultad de Ciencias Quı́micas y Farmacéuticas, Universidad de Chile, PO Box 174, Correo 22, Santiago, Chile1
| | - Mercedes Zaldı Var
- Departamento de Bioquı́mica y Biologı́a Molecular, Facultad de Ciencias Quı́micas y Farmacéuticas, Universidad de Chile, PO Box 174, Correo 22, Santiago, Chile1
| | - Cristina L Marolda
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada N6A 5C12
| | - Miguel A Valvano
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada N6A 5C12
| | - Inés Contreras
- Departamento de Bioquı́mica y Biologı́a Molecular, Facultad de Ciencias Quı́micas y Farmacéuticas, Universidad de Chile, PO Box 174, Correo 22, Santiago, Chile1
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99
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Zhao L, Ohtaki Y, Yamaguchi K, Matsushita M, Fujita T, Yokochi T, Takada H, Endo Y. LPS-induced platelet response and rapid shock in mice: contribution of O-antigen region of LPS and involvement of the lectin pathway of the complement system. Blood 2002; 100:3233-9. [PMID: 12384422 DOI: 10.1182/blood-2002-01-0252] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Intravenous injection of a lipopolysaccharide (LPS) into mice induces a rapid accumulation of platelets in the lung and liver. When degradation of the accumulated platelets occurs, anaphylactoid shock follows rapidly, the severity of the shock paralleling the quantity of platelets accumulated in the lung. Here we examined the contributions made by LPS structure and the complement system to the platelet response to LPS. BALB/c mice were injected with an LPS from Escherichia coli O8, O9, O111, or K-12, or from recombinant mutants of K-12. The O-regions of the O8 and O9 LPSs consist of a mannose homopolysaccharide (MHP), while that of O111 consists of a heteropolysaccharide (not including mannose), and K-12 LPS lacks an O-region. O111 LPS was devoid of the ability to induce the platelet response or shock, while the ability of K-12 LPS was weak. The 2 recombinant LPSs-each having an O-region (from O8 or O9) linked to K-12 LPS-exhibited activities similar to or stronger than those of their original LPSs. Mannose-binding lectin (MBL) complexed with MBL-associated serine proteases (MASPs) bound strongly to LPSs containing MHP and caused C4 activation. Moreover, the abilities of these LPSs to activate the complement system corresponded well with their abilities to induce the platelet response and rapid shock. These results suggest that the structure of the O-antigen region is important for the platelet response to LPS, and that activation of the lectin pathway of the complement system is involved in this response.
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Affiliation(s)
- Lijuan Zhao
- Departments of Oral Microbiology, Graduate School of Dentistry, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
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100
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Izquierdo L, Abitiu N, Coderch N, Hita B, Merino S, Gavin R, Tomás JM, Regué M. The inner-core lipopolysaccharide biosynthetic waaE gene: function and genetic distribution among some Enterobacteriaceae. MICROBIOLOGY (READING, ENGLAND) 2002; 148:3485-3496. [PMID: 12427940 DOI: 10.1099/00221287-148-11-3485] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
To determine the function of the waaE gene in the biosynthesis of the inner-core LPS of Klebsiella pneumoniae, a waaE non-polar mutant has been constructed. Data obtained from the comparative chemical analysis of LPS samples obtained from the wild-type, the mutant strain and the complemented mutant demonstrated that the waaE gene is involved in substitution of alpha-L-glycero-D-manno-heptopyranose I (L,D-HeppI) at the O-4 position by a beta-D-glucopyranose (beta-D-Glcp) residue. In addition, DNA amplification and nucleotide sequence determination studies revealed that waaE homologues located between the waaA and coaD genes are present in clinical isolates of Enterobacteriaceae containing the structure beta-D-Glcp-(1-->4)-alpha-L,D-HeppI (K. pneumoniae, Proteus mirabilis and Yersinia enterocolitica), as well as in strains of Serratia marcescens and Enterobacter aerogenes of unknown LPS-core structures. Complementation studies using non-polar waaE mutants prove that all the waaE homologues perform the same function. Furthermore, K. pneumoniae, Ser. marcescens and P. mirabilis non-polar waaE mutants showed reduced adhesion and pathogenicity. In addition, the Ser. marcescens and P. murabilis waaE mutants showed reduced swarming motility and ability to form biofilms in vitro. All these characteristics were rescued by reintroduction of the waaE gene independently of its origin. An easy DNA amplification method to detect this gene was established, which also helps in finding the potential presence of this structural feature [beta-D-Glcp-(1-->4)-alpha-L,D-HeppI] in the inner-core LPS of Enterobacteriaceae members with unknown LPS-core structures.
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Affiliation(s)
- Luis Izquierdo
- Departamento de Microbiologı́a, Facultad de Biologı́a, Universidad de Barcelona, Diagonal 645, 08071 Barcelona, Spain2
| | - Nihal Abitiu
- Departamento de Microbiologı́a y Parasitologı́a Sanitarias, División de Ciencias de la Salud, Facultad de Farmacia, Universidad de Barcelona, Av. Joan XXIII s/n, Barcelona 08028, Spain1
| | - Núria Coderch
- Departamento de Microbiologı́a y Parasitologı́a Sanitarias, División de Ciencias de la Salud, Facultad de Farmacia, Universidad de Barcelona, Av. Joan XXIII s/n, Barcelona 08028, Spain1
| | - Beatriz Hita
- Departamento de Microbiologı́a y Parasitologı́a Sanitarias, División de Ciencias de la Salud, Facultad de Farmacia, Universidad de Barcelona, Av. Joan XXIII s/n, Barcelona 08028, Spain1
| | - Susana Merino
- Departamento de Microbiologı́a, Facultad de Biologı́a, Universidad de Barcelona, Diagonal 645, 08071 Barcelona, Spain2
| | - Rosalina Gavin
- Departamento de Microbiologı́a, Facultad de Biologı́a, Universidad de Barcelona, Diagonal 645, 08071 Barcelona, Spain2
| | - Juan M Tomás
- Departamento de Microbiologı́a, Facultad de Biologı́a, Universidad de Barcelona, Diagonal 645, 08071 Barcelona, Spain2
| | - Miguel Regué
- Departamento de Microbiologı́a y Parasitologı́a Sanitarias, División de Ciencias de la Salud, Facultad de Farmacia, Universidad de Barcelona, Av. Joan XXIII s/n, Barcelona 08028, Spain1
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