Items 21-40 of 1302

    • Journal Article

      Taxon- and Site-Specific Melatonin Catabolism 

      Hardeland, Rüdiger
      Molecules 2017; 22(11): Art. 2015
      Melatonin is catabolized both enzymatically and nonenzymatically. Nonenzymatic processes mediated by free radicals, singlet oxygen, other reactive intermediates such as HOCl and peroxynitrite, or pseudoenzymatic mechanisms are not species- or tissue-specific, but vary considerably in their extent. Higher rates of nonenzymatic melatonin metabolism can be expected upon UV exposure, e.g., in plants and in the human skin. Additionally, melatonin is more strongly nonenzymatically degraded at sites of inflammation. Typical products are several hydroxylated derivatives of melatonin and N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK). Most of these products are also formed by enzymatic catalysis. Considerable taxon- and site-specific differences are observed in the main enzymatic routes of catabolism. Formation of 6-hydroxymelatonin by cytochrome P450 subforms are prevailing in vertebrates, predominantly in the liver, but also in the brain. In pineal gland and non-mammalian retina, deacetylation to 5-methoxytryptamine (5-MT) plays a certain role. This pathway is quantitatively prevalent in dinoflagellates, in which 5-MT induces cyst formation and is further converted to 5-methoxyindole-3-acetic acid, an end product released to the water. In plants, the major route is catalyzed by melatonin 2-hydroxylase, whose product is tautomerized to 3-acetamidoethyl-3-hydroxy-5-methoxyindolin-2-one (AMIO), which exceeds the levels of melatonin. Formation and properties of various secondary products are discussed.
      View Document Abstract
    • Journal Article

      Toward a monograph of non-marine Ulvophyceae using an integrative approach (Molecular phylogeny and systematics of terrestrial Ulvophyceae II.) 

      DARIENKO, TATYANA; PRÖSCHOLD, THOMAS
      Phytotaxa 2017; 324(1) p.001-041
      Phylogenetic analyses of SSU rDNA sequences have shown that coccoid and filamentous green algae are distributed among all classes of the Chlorophyta. One of these classes, the Ulvophyceae, mostly contains marine seaweeds and microalgae. However, new studies have shown that there are filamentous and sarcinoid freshwater and terrestrial species (including symbionts in lichens) among the Ulvophyceae, but very little is known about these species. Ultrastructural studies of some of them have confirmed that the flagellar apparatus of zoospores (counterclockwise basal body orientation) is typical for the Ulvophyceae. In addition to ultrastructural features, the presence of a “Codiolum”-stage is characteristic of some members of this algal class. We studied more than 50 strains of freshwater and terrestrial ulvophycean microalgae obtained from the different public culture collection and our own isolates using an integrative approach. Three independent lineages of the Ulvophyceae containing terrestrial species were revealed by these methods. Unexpectedly each of these lineages contained several isolates that morphologically developed a high degree of phenotypic plasticity, and included hidden phylogenetic diversity that let us to the description of several new genera and species.
      View Document Abstract
    • Journal Article

      A key role for foxQ2 in anterior head and central brain patterning in insects 

      Kitzmann, Peter; Weißkopf, Matthias; Schacht, Magdalena Ines; Bucher, Gregor
      Development 2017; 144(16) p.2969-2981
      Anterior patterning of animals is based on a set of highly conserved transcription factors but the interactions within the protostome anterior gene regulatory network (aGRN) remain enigmatic. Here, we identify the red flour beetle Tribolium castaneum ortholog of foxQ2 (Tc-foxQ2) as a novel upstream component of the aGRN. It is required for the development of the labrum and higher order brain structures, namely the central complex and the mushroom bodies. We reveal Tc-foxQ2 interactions by RNAi and heat shock-mediated misexpression. Surprisingly, Tc-foxQ2 and Tc-six3 mutually activate each other, forming a novel regulatory module at the top of the aGRN. Comparisons of our results with those of sea urchins and cnidarians suggest that foxQ2 has acquired more upstream functions in the aGRN during protostome evolution. Our findings expand the knowledge on foxQ2 gene function to include essential roles in epidermal development and central brain patterning.
      View Document Abstract
    • Journal Article

      Specific expression and function of the Six3 optix in Drosophila serially homologous organs 

      Al Khatib, Amer; Siomava, Natalia; Iannini, Antonella; Posnien, Nico; Casares, Fernando
      Biology Open 2017; 6(8) p.1155-1164
      Organ size and pattern results from the integration of two positional information systems. One global information system, encoded by the Hox genes, links organ type with position along the main body axis. Within specific organs, local information is conveyed by signaling molecules that regulate organ growth and pattern. The mesothoracic (T2) wing and the metathoracic (T3) haltere of Drosophila represent a paradigmatic example of this coordination. The Hox gene Ultrabithorax (Ubx), expressed in the developing T3, selects haltere identity by, among other processes, modulating the production and signaling efficiency of Dpp, a BMP2-like molecule that acts as a major regulator of size and pattern. However, the mechanisms of the Hox-signal integration in this well-studied system are incomplete. Here, we have investigated this issue by studying the expression and function of the Six3 transcription factor optix during Drosophila wing and haltere development. We find that in both organs, Dpp defines the expression domain of optix through repression, and that the specific position of this domain in wing and haltere seems to reflect the differential signaling profile among these organs. We show that optix expression in wing and haltere primordia is conserved beyond Drosophila in other higher diptera. In Drosophila, optix is necessary for the growth of wing and haltere. In the wing, optix is required for the growth of the most anterior/proximal region (the 'marginal cell') and for the correct formation of sensory structures along the proximal anterior wing margin; the halteres of optix mutants are also significantly reduced. In addition, in the haltere, optix is necessary for the suppression of sensory bristles.
      View Document Abstract
    • Journal Article

      Phylogeny reconstruction based on the length distribution of k-mismatch common substrings 

      Morgenstern, Burkhard; Schöbel, Svenja; Leimeister, Chris-André
      Algorithms for Molecular Biology 2017; 12(1): Art. 27
      Background: Various approaches to alignment-free sequence comparison are based on the length of exact or inexact word matches between pairs of input sequences. Haubold et al. (J Comput Biol 16:1487-1500, 2009) showed how the average number of substitutions per position between two DNA sequences can be estimated based on the average length of exact common substrings. Results: In this paper, we study the length distribution of k-mismatch common substrings between two sequences. We show that the number of substitutions per position can be accurately estimated from the position of a local maximum in the length distribution of their k-mismatch common substrings.
      View Document Abstract
    • Journal Article

      Changes in Nematode Communities and Functional Diversity With the Conversion of Rainforest Into Rubber and Oil Palm Plantations 

      Krashevska, Valentyna; Kudrin, Alexey A.; Widyastuti, Rahayu; Scheu, Stefan
      Frontiers in Ecology and Evolution 2019; 7: Art. 487
      Focusing on nematodes and their well-developed indices of community, ecosystem structure and function, we investigated the effects of the conversion of rainforest into rubber and oil palm plantations in Sumatra, Indonesia. Land use did not affect the total abundance of litter- and soil-dwelling nematodes, neither in riparian nor in well-drained sites. However, the rainforest nematode community differed from communities in plantations, with differences in litter being more pronounced compared to soil. In litter, fungivores and nematodes with short generation time (c-p2) increased in monoculture plantations, while that of bacterivores, herbivores, and nematodes with longer generation time and higher sensitivity to disturbances (c-p3) decreased. This indicates higher environmental pressure on nematodes in monoculture plantations than in rainforest. In soil of monoculture plantations, bacterivores, and c-p3 nematodes decreased while herbivores increased. This suggests that the damage of plants by nematodes in oil palm plantations exceeds that in rainforest. Overall, nematode functional diversity indices suggest that the stability of the decomposer community is higher in rainforest compared to monoculture plantations. Importantly, functional diversity indices were much more meaningful than nematode abundance. Further, changes with land use manifested more in litter than in soil, reflecting that nematode communities in soil are buffered against changes in land use and associated environmental conditions. Therefore, to fully assess changes in the structure and functioning of decomposer systems with changes in land use, the litter layer, which often receives little attention, requires more careful consideration.
      View Document Abstract
    • Journal Article

      Editorial: Diversity and Universality in Causal Cognition 

      Beller, Sieghard; Bender, Andrea; Waldmann, Michael R.
      Frontiers in Psychology 2017; 8: Art. 1767
      View Document
    • Journal Article

      A Randomized Controlled Trial on Functional Relaxation as an Adjunct to Psychoeducation for Stress 

      Lahmann, Claas; Gebhardt, Maria; Sattel, Heribert; Dinkel, Andreas; Pieh, Christoph; Probst, Thomas
      Frontiers in Psychology 2017; 8: Art. 1553
      This randomized controlled trial investigated whether adding the psychodynamically based body-oriented psychotherapy "Functional Relaxation" (FR) to psychoeducation (PE) is more effective than PE alone to reduce stress and stress-associated complaints. Eighty-one participants with elevated stress-levels, ≥50 points on the global scale of the Perceived Stress Questionnaire (PSQ), received either 10 sessions of manualized FR + PE (n = 42) or two sessions of manualized PE alone (n = 39) in a group setting. Six FR trainers took part in this study. Stress-level (PSQ) was the primary outcome and secondary outcomes were depression (PHQ-9) and somatization (PHQ-15). Multilevel models for discontinuous change revealed that FR + PE was more helpful to reduce stress-levels than PE from pre-treatment to post-treatment (t0 → t1) as well as from pre-treatment to 6-month follow-up (t0 → t2) (both p < 0.05) with effect sizes (d) being medium for PE (dt0 → t1 = 0.57; dt0 → t2 = 0.67) and large for FR + PE (dt0 → t1 = 1.57; dt0 → t2 = 1.39). Moreover, FR + PE affected depression and somatization more positively than did PE from t0 to t1 as well as from t0 to t2 (all p < 0.05). Effect sizes for depression were small to medium for PE (dt0 → t1 = 0.52; dt0 → t2 = 0.37) and large for FR + PE (dt0 → t1 = 1.04; dt0 → t2 = 0.95). Effect sizes for somatization were small for PE (dt0 → t1 = 0.18; dt0 → t2 = 0.19) and medium to large for FR + PE (dt0 → t1 = 0.73; dt0 → t2 = 0.93). In summary, the combination of FR and PE was more effective than PE alone. The results of the present trial provide first evidence of FR as a potent component of stress interventions. Adding FR to such interventions might better help prevent clinically relevant disorders such as depression or somatization.
      View Document Abstract
    • Journal Article

      Predominant colonization of Malesian mountains by Australian tree lineages 

      Brambach, Fabian; Leuschner, Christoph; Tjoa, Aiyen; Culmsee, Heike
      Journal of Biogeography p.1-16
      Abstract Aim: Massive biota mixing due to plate‐tectonic movement has shaped the biogeography of Malesia and during the colonization process, Asian plant lineages have presumably been more successful than their Australian counterparts. We aim to gain a deeper understanding of this colonization asymmetry and its underlying mechanisms by analysing how species richness and abundance of Asian versus Australian tree lineages in three Malesian subregions change along environmental gradients. We hypothesize that differing environmental histories of Asia and Australia, and their relation to habitats in Malesia, have been important factors driving assembly patterns of the Malesian flora. Location: Malesia, particularly Sundaland, the Philippines and Wallacea. Taxon: Seed plants (trees). Methods: We compiled plot‐level data of environmental variables and tree abundances from three Malesian subregions. For each species, we inferred its geographical ancestry (Asian or Australian) based on published phylogenetic studies and the fossil record. We used proportions of Australian versus Asian species and individuals per plot to test how they are related to environmental parameters and geographical position using logistic regression models. Results: Proportionally more Australian (and fewer Asian) tree species and individuals occurred (a) at higher elevations, (b) on sites over ultramafic parent material and (c) closer to their source region Australia with a significant increase of Australian elements east of Wallace's line. The trend was stronger for individuals than for species. Main conclusions: Long‐term environmental similarities between source and sink habitats have shaped the assembly of the Malesian flora: Tree lineages from tropical Southeast Asia predominantly colonized the Malesian lowlands and rich soils, whereas trees from montane refuges in Australia were more successful in the newly emerging Malesian mountains and on poorer soils. The biogeographical patterns caused by the Malesian Floristic Interchange point to the importance of phylogenetic biome conservatism in biotic interchanges and resemble
      View Document Abstract
    • Journal Article

      Mapping Cellular Microenvironments: Proximity Labeling and Complexome Profiling (Seventh Symposium of the Göttingen Proteomics Forum) 

      Valerius, Oliver; Asif, Abdul R.; Beißbarth, Tim; Bohrer, Rainer; Dihazi, Hassan; Feussner, Kirstin; Jahn, Olaf; Majcherczyk, Andrzej; Schmidt, Bernhard; Schmitt, Kerstin; et al.
      Urlaub, HenningLenz, Christof
      Cells 2019; 8(10): Art. 1192
      Mass spectrometry-based proteomics methods are finding increasing use in structural biology research. Beyond simple interaction networks, information about stable protein-protein complexes or spatially proximal proteins helps to elucidate the biological functions of proteins in a wider cellular context. To shed light on new developments in this field, the Göttingen Proteomics Forum organized a one-day symposium focused on complexome profiling and proximity labeling, two emerging technologies that are gaining significant attention in biomolecular research. The symposium was held in Göttingen, Germany on 23 May, 2019, as part of a series of regular symposia organized by the Göttingen Proteomics Forum.
      View Document Abstract
    • Journal Article

      Phylogenetic analysis of phenotypic characters of Tunicata supports basal Appendicularia and monophyletic Ascidiacea 

      Braun, Katrin; Leubner, Fanny; Stach, Thomas
      Cladistics p.1-42
      With approximately 3000 marine species, Tunicata represents the most disparate subtaxon of Chordata. Molecular phylogenetic studies support Tunicata as sister taxon to Craniota, rendering it pivotal to understanding craniate evolution. Although successively more molecular data have become available to resolve internal tunicate phylogenetic relationships, phenotypic data have not been utilized consistently. Herein these shortcomings are addressed by cladistically analyzing 117 phenotypic characters for 49 tunicate species comprising all higher tunicate taxa, and five craniate and cephalochordate outgroup species. In addition, a combined analysis of the phenotypic characters with 18S rDNA‐sequence data is performed in 32 OTUs. The analysis of the combined data is congruent with published molecular analyses. Successively up‐weighting phenotypic characters indicates that phenotypic data contribute disproportionally more to the resulting phylogenetic hypothesis. The strict consensus tree from the analysis of the phenotypic characters as well as the single most parsimonious tree found in the analysis of the combined dataset recover monophyletic Appendicularia as sister taxon to the remaining tunicate taxa. Thus, both datasets support the hypothesis that the last common ancestor of Tunicata was free‐living and that ascidian sessility is a derived trait within Tunicata. “Thaliacea” is found to be paraphyletic with Pyrosomatida as sister taxon to monophyletic Ascidiacea and the relationship between Doliolida and Salpida is unresolved in the analysis of morphological characters; however, the analysis of the combined data reconstructs Thaliacea as monophyletic nested within paraphyletic “Ascidiacea”. Therefore, both datasets differ in the interpretation of the evolution of the complex holoplanktonic life history of thaliacean taxa. According to the phenotypic data, this evolution occurred in the plankton, whereas from the combined dataset a secondary transition into the plankton from a sessile ascidian is inferred. Besides these major differences, both analyses are in accord on many phylogenetic groupings, although both phylogenetic reconstructions invoke a high degree of homoplasy. In conclusion, this study represents the first serious attempt to utilize the potential phylogenetic information present in phenotypic characters to elucidate the inter‐relationships of this diverse marine taxon in a consistent cladistic framework.
      View Document Abstract
    • Journal Article

      The effectiveness of livestock protection measures against wolves (Canis lupus) and implications for their co-existence with humans 

      Bruns, Antonia; Waltert, Matthias; Khorozyan, Igor
      Global Ecology and Conservation 2020; 21: Art. e00868
      Wolves (Canis lupus) can kill domestic livestock resulting in intense conflicts with humans. Damage to livestock should be reduced to facilitate human-wolf coexistence and ensure positive outcomes of conservation efforts. Current knowledge on the effectiveness of livestock protection measures from wolves is limited and scattered in the literature. In this study, we compiled a dataset of 30 cases describing the application of 11 measures of protecting cattle and smaller livestock against wolves, estimated their effectiveness as a relative risk of damage, and identified the best measures for damage reduction. We found that: (1) lethal control and translocation were less effective than other measures, (2) deterrents, especially fladry which is a fence with ropes marked by hanging colored flags that sway in the wind and provide a visual warning signal, were more effective than guarding dogs; (3) deterrents, fencing, calving control and herding were very effective, but the last two measures included only one case each; and (4) protection of cattle was more effective than that of small stock (sheep and goats, or sheep only) and mixed cattle and small stock. In all of these cases, the relative risk of damage was reduced by 50–100%. Considering Germany as an example of a country with a recovering wolf population and escalating human-wolf conflicts, we suggest electric fences and electrified fladry as the most promising measures, which under suitable conditions can be accompanied by well-trained livestock guarding dogs, and the temporary use of deterrents during critical periods such as calving and lambing seasons. Further research in this field is of paramount importance to efficiently mitigate human-wolf conflicts.
      View Document Abstract
    • Journal Article

      The contribution of bacterial genome engineering to sustainable development 

      Reuß, Daniel R.; Commichau, Fabian M.; Stülke, Jörg
      Microbial Biotechnology 2017; 10(5) p.1259-1263
      The United Nations' Sustainable Development Goals define important challenges for the prosperous development of mankind. To reach several of these goals, among them the production of value-added compounds, improved economic and ecologic balance of production processes, prevention of climate change and protection of ecosystems, the use of engineered bacteria can make valuable contributions. We discuss the strategies for genome engineering and how they can be applied to meet the United Nations' goals for sustainable development.
      View Document Abstract
    • View Document
    • Journal Article

      Sphingomonas jeddahensis sp. nov., isolated from Saudi Arabian desert soil 

      Wübbeler, Jan Hendrik; Oppermann-Sanio, Fred Bernd; Ockenfels, Andrea; Röttig, Annika; Osthaar-Ebker, Alena; Verbarg, Susanne; Poehlein, Anja; Madkour, Mohamed H.; Al-Ansari, Ahmed M.; Almakishah, Naief H.; et al.
      Daniel, RolfSteinbüchel, Alexander
      International Journal of Systematic and Evolutionary Microbiology 2017; 67(10) p.4057-4063
      A novel Sphingomonas strain was isolated from a sample of desert soil collected near Jeddah in Saudi Arabia. A polyphasic approach was performed to characterize this strain, initially designated as G39T. Cells of strain G39T are motile, Gram-negative, catalase- and oxidase-positive. The strain is able to grow aerobically at 20-35 °C, pH 6.5-8 and tolerates up to 4 % (w/v) NaCl. Based on 16S rRNA gene sequence similarity, the closest relative type strains of G39T are Sphingomonas mucosissima DSM 17494T (98.6 %), S. dokdonensis DSM 21029T (98.4 %) and S. hankookensis DSM 23329T (97.4 %). Furthermore, the average nucleotide identities between the draft genome sequence of strain G39T and the genome sequences of all other available and related Sphingomonas species are significantly below the threshold of 94 %. The G+C content of the draft genome (3.12 Mbp) is 65.84 %. The prevalent (>5 %) cellular fatty acids of G39T were C18 : 1ω7c, C16 : 1ω7c and/or C16 : 1ω6c, C14 : 0 2-OH and C16 : 0. The only detectable respiratory quinone was ubiquinone-10 and the polar lipids profile is composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, as well as unidentified lipids, phospholipids and glycolipids. The results of the conducted polyphasic approach confirmed that this isolate represents a novel species of the genus Sphingomonas, for which the name Sphingomonas jeddahensis sp. nov. is proposed. The type strain of this species is G39T (=DSM 103790T=LMG 29955T).
      View Document Abstract
    • Journal Article

      Postglacial change of the floristic diversity gradient in Europe 

      Giesecke, Thomas; Wolters, Steffen; van Leeuwen, Jacqueline F. N.; van der Knaap, Pim W. O.; Leydet, Michelle; Brewer, Simon
      Nature Communications 2019; 10(1): Art. 5422
      Climate warming is expected to cause a poleward spread of species, resulting in increased richness at mid to high latitudes and weakening the latitudinal diversity gradient. We used pollen data to test if such a change in the latitudinal diversity gradient occurred during the last major poleward shift of plant species in Europe following the end of the last glacial period. In contrast to expectations, the slope of the gradient strengthened during the Holocene. The increase in temperatures around 10 ka ago reduced diversity at mid to high latitude sites due to the gradual closure of forests. Deforestation and the introduction of agriculture during the last 5 ky had a greater impact on richness in central Europe than the earlier climate warming. These results do not support the current view that global warming alone will lead to a loss in biodiversity, and demonstrate that non-climatic human impacts on the latitudinal diversity gradient is of a greater magnitude than climate change.
      View Document Abstract
    • Journal Article

      Analysis of IFITM-IFITM Interactions by a Flow Cytometry-Based FRET Assay 

      Winkler, Michael; Wrensch, Florian; Bosch, Pascale; Knoth, Maike; Schindler, Michael; Gärtner, Sabine; Pöhlmann, Stefan
      International Journal of Molecular Sciences 2019; 20(16): Art. 3859
      The interferon-induced transmembrane proteins 1-3 (IFITM1-3) inhibit host cell entry of several viruses. However, it is incompletely understood how IFITM1-3 exert antiviral activity. Two phenylalanine residues, F75 and F78, within the intramembrane domain 1 (IM1) were previously shown to be required for IFITM3/IFITM3 interactions and for inhibition of viral entry, suggesting that IFITM/IFITM interactions might be pivotal to antiviral activity. Here, we employed a fluorescence resonance energy transfer (FRET) assay to analyze IFITM/IFITM interactions. For assay calibration, we equipped two cytosolic, non-interacting proteins, super yellow fluorescent protein (SYFP) and super cyan fluorescent protein (SCFP), with signals that target proteins to membrane rafts and also analyzed a SCFP-SYFP fusion protein. This strategy allowed us to discriminate background signals resulting from colocalization of proteins at membrane subdomains from signals elicited by protein-protein interactions. Coexpression of IFITM1-3 and IFITM5 fused to fluorescent proteins elicited strong FRET signals, and mutation of F75 and F78 in IFITM3 (mutant IFITM3-FF) abrogated antiviral activity, as expected, but did not alter cellular localization and FRET signals. Moreover, IFITM3-FF co-immunoprecipitated efficiently with wild type (wt) IFITM3, lending further support to the finding that lack of antiviral activity of IFITM3-FF was not due to altered membrane targeting or abrogated IFITM3-IFITM3 interactions. Collectively, we report an assay that allows quantifying IFITM/IFITM interactions. Moreover, we confirm residues F75 and F78 as critical for antiviral activity but also show that these residues are dispensable for IFITM3 membrane localization and IFITM3/IFITM3 interactions.
      View Document Abstract
    • Journal Article

      Comparing Open-Source Toolboxes for Processing and Analysis of Spike and Local Field Potentials Data 

      Unakafova, Valentina A.; Gail, Alexander
      Frontiers in Neuroinformatics 2019; 13: Art. 57
      Analysis of spike and local field potential (LFP) data is an essential part of neuroscientific research. Today there exist many open-source toolboxes for spike and LFP data analysis implementing various functionality. Here we aim to provide a practical guidance for neuroscientists in the choice of an open-source toolbox best satisfying their needs. We overview major open-source toolboxes for spike and LFP data analysis as well as toolboxes with tools for connectivity analysis, dimensionality reduction and generalized linear modeling. We focus on comparing toolboxes functionality, statistical and visualization tools, documentation and support quality. To give a better insight, we compare and illustrate functionality of the toolboxes on open-access dataset or simulated data and make corresponding MATLAB scripts publicly available.
      View Document Abstract
    • Journal Article

      Local field potentials are induced by visually evoked spiking activity in macaque cortical area MT 

      Esghaei, Moein; Daliri, Mohammad Reza; Treue, Stefan
      Scientific Reports 2017; 7(1)
      Local field potentials (LFP) have been the focus of many recent studies in systems neuroscience. However, the exact neural basis of these signals remains unclear. To address this question, we determined the relationship between LFP signals and another, much better understood, signature of neural activity: action potentials. Specifically, we focused on the relationship between the amplitude of stimulus-induced LFPs and the magnitude of spiking activity in visual cortex of non-human primates. Our trial-by-trial correlation analyses between these two components of extracellular signals in macaque visual cortex show that the spike rate is coupled to the LFP amplitude with a surprisingly long latency, typically 50 ms. Our analysis shows that the neural spike rate is a significant predictor of the LFP amplitude. This limits the functional interpretation of LFP signals beyond that based on spiking activities.
      View Document Abstract
    • Journal Article

      A metagenome-derived thermostable β-glucanase with an unusual module architecture which defines the new glycoside hydrolase family GH148 

      Angelov, Angel; Pham, Vu Thuy Trang; Übelacker, Maria; Brady, Silja; Leis, Benedikt; Pill, Nicole; Brolle, Judith; Mechelke, Matthias; Moerch, Matthias; Henrissat, Bernard; et al.
      Liebl, Wolfgang
      Scientific Reports 2017; 7(1)
      The discovery of novel and robust enzymes for the breakdown of plant biomass bears tremendous potential for the development of sustainable production processes in the rapidly evolving new bioeconomy. By functional screening of a metagenomic library from a volcano soil sample a novel thermostable endo-β-glucanase (EngU) which is unusual with regard to its module architecture and cleavage specificity was identified. Various recombinant EngU variants were characterized. Assignment of EngU to an existing glycoside hydrolase (GH) family was not possible. Two regions of EngU showed weak sequence similarity to proteins of the GH clan GH-A, and acidic residues crucial for catalytic activity of EngU were identified by mutation. Unusual, a carbohydrate-binding module (CBM4) which displayed binding affinity for β-glucan, lichenin and carboxymethyl-cellulose was found as an insertion between these two regions. EngU hydrolyzed β-1,4 linkages in carboxymethyl-cellulose, but displayed its highest activity with mixed linkage (β-1,3-/β-1,4-) glucans such as barley β-glucan and lichenin, where in contrast to characterized lichenases cleavage occurred predominantly at the β-1,3 linkages of C4-substituted glucose residues. EngU and numerous related enzymes with previously unknown function represent a new GH family of biomass-degrading enzymes within the GH-A clan. The name assigned to the new GH family is GH148.
      View Document Abstract