Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2012-06-16
    Description: Pathogenic bacteria using a type III secretion system (T3SS) to manipulate host cells cause many different infections including Shigella dysentery, typhoid fever, enterohaemorrhagic colitis and bubonic plague. An essential part of the T3SS is a hollow needle-like protein filament through which effector proteins are injected into eukaryotic host cells. Currently, the three-dimensional structure of the needle is unknown because it is not amenable to X-ray crystallography and solution NMR, as a result of its inherent non-crystallinity and insolubility. Cryo-electron microscopy combined with crystal or solution NMR subunit structures has recently provided a powerful hybrid approach for studying supramolecular assemblies, resulting in low-resolution and medium-resolution models. However, such approaches cannot deliver atomic details, especially of the crucial subunit-subunit interfaces, because of the limited cryo-electron microscopic resolution obtained in these studies. Here we report an alternative approach combining recombinant wild-type needle production, solid-state NMR, electron microscopy and Rosetta modelling to reveal the supramolecular interfaces and ultimately the complete atomic structure of the Salmonella typhimurium T3SS needle. We show that the 80-residue subunits form a right-handed helical assembly with roughly 11 subunits per two turns, similar to that of the flagellar filament of S. typhimurium. In contrast to established models of the needle in which the amino terminus of the protein subunit was assumed to be alpha-helical and positioned inside the needle, our model reveals an extended amino-terminal domain that is positioned on the surface of the needle, while the highly conserved carboxy terminus points towards the lumen.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3598588/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3598588/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Loquet, Antoine -- Sgourakis, Nikolaos G -- Gupta, Rashmi -- Giller, Karin -- Riedel, Dietmar -- Goosmann, Christian -- Griesinger, Christian -- Kolbe, Michael -- Baker, David -- Becker, Stefan -- Lange, Adam -- 1R01GM092802-01/GM/NIGMS NIH HHS/ -- R01 GM092802/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2012 May 20;486(7402):276-9. doi: 10.1038/nature11079.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, 37077 Gottingen, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22699623" target="_blank"〉PubMed〈/a〉
    Keywords: *Bacterial Secretion Systems ; HeLa Cells ; Humans ; Microscopy, Electron ; *Models, Molecular ; Nuclear Magnetic Resonance, Biomolecular ; Protein Structure, Secondary ; Salmonella typhimurium/*chemistry
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2015-10-23
    Description: The anaerobic oxidation of methane (AOM) with sulfate controls the emission of the greenhouse gas methane from the ocean floor. In marine sediments, AOM is performed by dual-species consortia of anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB) inhabiting the methane-sulfate transition zone. The biochemical pathways and biological adaptations enabling this globally relevant process are not fully understood. Here we study the syntrophic interaction in thermophilic AOM (TAOM) between ANME-1 archaea and their consortium partner SRB HotSeep-1 (ref. 6) at 60 degrees C to test the hypothesis of a direct interspecies exchange of electrons. The activity of TAOM consortia was compared to the first ANME-free culture of an AOM partner bacterium that grows using hydrogen as the sole electron donor. The thermophilic ANME-1 do not produce sufficient hydrogen to sustain the observed growth of the HotSeep-1 partner. Enhancing the growth of the HotSeep-1 partner by hydrogen addition represses methane oxidation and the metabolic activity of ANME-1. Further supporting the hypothesis of direct electron transfer between the partners, we observe that under TAOM conditions, both ANME and the HotSeep-1 bacteria overexpress genes for extracellular cytochrome production and form cell-to-cell connections that resemble the nanowire structures responsible for interspecies electron transfer between syntrophic consortia of Geobacter. HotSeep-1 highly expresses genes for pili production only during consortial growth using methane, and the nanowire-like structures are absent in HotSeep-1 cells isolated with hydrogen. These observations suggest that direct electron transfer is a principal mechanism in TAOM, which may also explain the enigmatic functioning and specificity of other methanotrophic ANME-SRB consortia.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wegener, Gunter -- Krukenberg, Viola -- Riedel, Dietmar -- Tegetmeyer, Halina E -- Boetius, Antje -- England -- Nature. 2015 Oct 22;526(7574):587-90. doi: 10.1038/nature15733.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max-Planck Institute for Marine Microbiology, 28359 Bremen, Germany. ; MARUM, Center for Marine Environmental Sciences, University Bremen, 28359 Bremen, Germany. ; Max Planck Institute for Biophysical Chemistry, 37077 Gottingen, Germany. ; Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, 27570 Bremerhaven, Germany. ; Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26490622" target="_blank"〉PubMed〈/a〉
    Keywords: Anaerobiosis ; Archaea/*metabolism ; Bacteria/*metabolism ; Cytochromes/metabolism ; Electron Transport ; Fimbriae, Bacterial/metabolism ; Geologic Sediments/microbiology ; Heme/metabolism ; Hydrogen/metabolism ; Hydrothermal Vents/microbiology ; Methane/*metabolism ; Microbiota/physiology ; Molecular Sequence Data ; Oceans and Seas ; Sulfates/metabolism ; Symbiosis ; Temperature
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2012-06-02
    Description: Cellular membrane fusion is thought to proceed through intermediates including docking of apposed lipid bilayers, merging of proximal leaflets to form a hemifusion diaphragm, and fusion pore opening. A membrane-bridging four-helix complex of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) mediates fusion. However, how assembly of the SNARE complex generates docking and other fusion intermediates is unknown. Using a cell-free reaction, we identified intermediates visually and then arrested the SNARE fusion machinery when fusion was about to begin. Partial and directional assembly of SNAREs tightly docked bilayers, but efficient fusion and an extended form of hemifusion required assembly beyond the core complex to the membrane-connecting linkers. We propose that straining of lipids at the edges of an extended docking zone initiates fusion.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3677693/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3677693/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hernandez, Javier M -- Stein, Alexander -- Behrmann, Elmar -- Riedel, Dietmar -- Cypionka, Anna -- Farsi, Zohreh -- Walla, Peter J -- Raunser, Stefan -- Jahn, Reinhard -- 3P01GM072694-05S1/GM/NIGMS NIH HHS/ -- P01 GM072694/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2012 Jun 22;336(6088):1581-4. doi: 10.1126/science.1221976. Epub 2012 May 31.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Gottingen, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22653732" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Lipid Bilayers/chemistry/*metabolism ; *Liposomes/chemistry/metabolism ; *Membrane Fusion ; Protein Binding ; Protein Conformation ; Rats ; SNARE Proteins/chemistry/*metabolism ; Vesicle-Associated Membrane Protein 2/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2016-02-26
    Description: Synaptic transmission is mediated by the release of neurotransmitters, which involves exo-endocytotic cycling of synaptic vesicles. To maintain synaptic function, synaptic vesicles are refilled with thousands of neurotransmitter molecules within seconds after endocytosis, using the energy provided by an electrochemical proton gradient. However, it is unclear how transmitter molecules carrying different net charges can be efficiently sequestered while maintaining charge neutrality and osmotic balance. We used single-vesicle imaging to monitor pH and electrical gradients and directly showed different uptake mechanisms for glutamate and gamma-aminobutyric acid (GABA) operating in parallel. In contrast to glutamate, GABA was exchanged for protons, with no other ions participating in the transport cycle. Thus, only a few components are needed to guarantee reliable vesicle filling with different neurotransmitters.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Farsi, Zohreh -- Preobraschenski, Julia -- van den Bogaart, Geert -- Riedel, Dietmar -- Jahn, Reinhard -- Woehler, Andrew -- New York, N.Y. -- Science. 2016 Feb 26;351(6276):981-4. doi: 10.1126/science.aad8142. Epub 2016 Feb 11.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, 37077 Gottingen, Germany. ; Department of Tumor Immunology, Radboud University Medical Center, 6525GA Nijmegen, Netherlands. ; Laboratory of Electron Microscopy, Max Planck Institute for Biophysical Chemistry, 37077 Gottingen, Germany. ; Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, 37077 Gottingen, Germany. rjahn@gwdg.de. ; Department of Membrane Biophysics, Max Planck Institute for Biophysical Chemistry, 37077 Gottingen, Germany. Deutsche Forschungsgemeinschaft (DFG) Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Gottingen, 37073, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26912364" target="_blank"〉PubMed〈/a〉
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    Keywords: CELLS ; EXPRESSION ; BLOOD ; human ; PATHWAYS ; NETWORK ; DISEASE ; DISTINCT ; GENE ; GENE-EXPRESSION ; GENES ; microarray ; PROTEIN ; COMPLEX ; NITRIC-OXIDE ; RESPONSES ; COMPLEXES ; TARGET ; ELEMENT-BINDING-PROTEIN ; IDENTIFICATION ; PATTERNS ; STRESS ; transgenic ; RESPONSIVE ELEMENT ; HeLa cells ; OXIDATIVE STRESS ; gene expression profiling ; CELL- SURFACE EXPRESSION ; FERRITIN MESSENGER-RNA ; HEREDITARY HEMOCHROMATOSIS PROTEIN ; POSTTRANSCRIPTIONAL REGULATION ; TRANSFERRIN RECEPTOR GENE ; TRANSLATIONAL REGULATION
    Abstract: Specialized cDNA-based microarrays (Ironchips) were developed to investigate complex physiological gene-regulatory patterns in iron metabolism. Approximately 115 human cDNAs were strategically selected to represent genes involved either in iron metabolism or in interlinked pathways (eg, oxidative stress, nitric oxide [NO] metabolism, or copper metabolism), and were immobilized on glass slides. HeLa cells were treated with iron donors or iron chelators, or were subjected to oxidative stress (H2O2) or NO (sodium nitroprusside). In addition, we generated a stable transgenic HeLa cell line expressing the HFE gene under an inducible promoter. Gene- response patterns were recorded for all of these interrelated experimental stimuli, and analyzed for common and distinct responses that define signal-specific regulatory patterns. The resulting regulatory patterns reveal and define degrees of relationship between distinct signals. Remarkably, the gene responses elicited by the altered expression of the hemochromatosis protein HFE and by pharmacological iron chelation exhibit the highest degree of relatedness, both for iron-regulatory protein (IRP) and non-IRP target genes. This finding suggests that HFE expression directly affects the intracellular chelatable iron pool in the transgenic cell line. Furthermore, cells treated with the iron donors hemin or ferric ammonium citrate display response patterns that permit the identification of the iron-loaded state in both cases, and the discrimination between the sources of iron loading. These findings also demonstrate the broad utility of gene-expression profiling with the IronChip to study iron metabolism and related human diseases. (C) 2003 by The American Society of Hematology
    Type of Publication: Journal article published
    PubMed ID: 12393473
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    facet.materialart.
    Unknown
    German Medical Science GMS Publishing House; Düsseldorf
    In:  78. Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e.V.; 20070516-20070520; München; DOC07hnod236 /20070424/
    Publication Date: 2007-04-24
    Keywords: ddc: 610
    Language: English
    Type: conferenceObject
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary.  Antisera to the bacterially expressed nonstructural proteins (NSP) HC-Pro, CI, NIa, and NIb and the coat protein (CP) of plum pox potyvirus (PPV) were used for analysing the composition of virus-induced cytoplasmic and nuclear inclusions by electron microscopy. The antisera reacted with NSP and CP of PPV on immunogold-labelled ultrathin sections. Antiserum to CP reacted with virions of seven out of 18 other potyviruses. CP was distributed throughout the cytoplasm of infected cells. Antisera to PPV NSP specifically reacted with virus-specific cytoplasmic and/or nuclear inclusions induced by 17 different potyviruses. NSP were furthermore localized in confined cytoplasmic areas in between complex accumulations of virus-specific inclusions. Cylindrical inclusions induced by the potyviruses were proven to consist of CI protein. Most other cytoplasmic or nuclear inclusions were shown to be composed of two or more NSP. An unexpected composition of virus-induced inclusions was observed for the crystalline nuclear inclusions of tobacco etch virus. Here, in addition to the expected presence of NIa and NIb, HC-Pro could be demonstrated. Furthermore, amorphous cytoplasmic inclusions induced by papaya ringspot virus contained the expected HC-Pro but additionally NIa, NIb and CI. Beet mosaic virus-induced nuclear inclusions (‘satellite bodies’) contained in their electron-dense matrix NIa, NIb, Hc-Pro and CI and in their lacunae CP in bundles of virion-like filaments. The results indicate that all cytoplasmic or nuclear inclusions of potyviruses have to be regarded as deposition sites of excessively produced viral NSP.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Notes: Abstract The total dissolved load of the Rhine river increases downstream due to the combined impact of natural and pollution loads. The natural background, controlled by geology, is soon swamped by pollution, particularly from salt and coal mining activities in Alsace and the Ruhr area. The Rhine is also a net source of CO2 from oxidation of excess organic productivity that is fuelled by nutrient pollution, a problem even more serious for some of its tributaries.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1432-0703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract This is a report on exposure to and absorption of the herbicide 2,4-D dimethylamine salt by farmers carrying out spray operations with tractor-drawn ground-rigs, involving handling, transferring, mixing, and applying the herbicide to wheat. The 30 individual spray operations lasted 55 to 870 min, and involved 1 to 11 tank fills, and application of 6.7 to 88.3 kg 2,4-D (acid equivalent, a.e.) to 16 to 194 ha. Air sampling, hand washes and clothing patch techniques served as a basis to calculate the amount of 2,4-D available for inhalation, and deposition on the hands and under the clothing. The “cumulative potential exposure” was calculated as the total amount of 2,4-D (a.e.) which could have come into contact with the body by both the inhalation and dermal routes of exposure. The calculated amount inhaled accounted for less than 2% of the calculated potential cumulative exposure, while deposition on the hands accounted for 80 to 90% of the potential cumulative exposure. The 2,4-D deposition on the rest of the body ranged from 10 to 20% of the potential cumulative exposure. Urinary 2,4-D excretion accounted for 1 to 2% of the potential cumulative exposure. The total calculated amount of 2,4-D deposited on the body (minus the hands) and the total amount excreted in the urine were highly correlated with the number of tank fills, area sprayed, amount sprayed, and duration of the spray operation.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-0630
    Keywords: PACS: 42.65; 81.40; 61.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract. First measurements of effective absorption coefficient and penetration depth are given here from the ablation of poly-methylmethacrylate (PMMA) and poly-tetrafluoroethylene (PTFE) samples at 125 nm (≈10 eV). The coherent VUV source used which provides smooth, efficient and clean etched areas, is briefly described. Experimental curves of etch depth as a function of the number of laser shots and etch rate as a function of energy density are obtained and compared with previous works performed at 157 nm (F2 laser) and 193 nm (ArF laser). Experimental results are described with a Beer–Lambert absorption law and discussed.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...