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131.
Birgit Hoff Jens Kamerewerd Claudia Sigl Ivo Zadra Ulrich Kück 《Applied microbiology and biotechnology》2010,85(4):1081-1094
In Penicillium chrysogenum, the industrial producer of the β-lactam antibiotic penicillin, generating gene replacements for functional analyses is very
inefficient. Here, we constructed a recipient strain that allows efficient disruption of any target gene via homologous recombination.
Following isolation of the Pcku70 (syn. hdfA) gene encoding a conserved eukaryotic DNA-binding protein involved in non-homologous end joining (NHEJ), a Pcku70 knockout strain was constructed using a novel nourseothricin-resistance cassette as selectable marker. In detailed physiological
tests, strain ΔPcku70 showed no significant reduction in vegetative growth due to increased sensitivity to different mutagenic
substances. Importantly, deletion of the Pcku70 gene had no effect on penicillin biosynthesis. However, strain ΔPcku70 exhibits higher sensitivity to osmotic stress than
the parent strain. This correlated well with comparative data from microarray analyses: Genes related to the stress response
are significantly up-regulated in the Pcku70 deletion mutant. To demonstrate the applicability of strain ΔPcku70, three genes related to β-lactam antibiotic biosynthesis
were efficiently disrupted, indicating that this strain shows a low frequency of NHEJ, thus promoting efficient homologous
recombination. Furthermore, we discuss strategies to reactivate Pcku70 in strains successfully used for gene disruptions. 相似文献
132.
Christina Liedert Jörg Bernhardt Dirk Albrecht Birgit Voigt Michael Hecker Mirja Salkinoja‐Salonen Peter Neubauer 《Proteomics》2010,10(3):555-563
2‐DE reference maps for Deinococcus geothermalis cytosolic and cell envelope proteomes were constructed. In total, 403 spots were identified as 299 different proteins. Unique in the proteomes were four subunits of V‐type ATPase and Deinococcus specific proteins constituting one‐fourth of cell envelope proteome. The cytoplasmic proteome included enzymes of the central carbon metabolism, chaperones, enzymes of protein and DNA repair, and oxidative stress. A total of 34 abundant proteins with unknown function may relate to the extreme stress tolerance of D. geothermalis. 相似文献
133.
134.
Nicholas Schramek Huahong Wang Werner Römisch-Margl Birgit Keil Tanja Radykewicz Bernhard Winzenhörlein Ludger Beerhues Adelbert Bacher Felix Rohdich Jonathan Gershenzon Benye Liu Wolfgang Eisenreich 《Phytochemistry》2010,71(2-3):179-187
Artemisinin from Artemisia annua has become one of the most important drugs for malaria therapy. Its biosynthesis proceeds via amorpha-4,11-diene, but it is still unknown whether the isoprenoid precursors units are obtained by the mevalonate pathway or the more recently discovered non-mevalonate pathway. In order to address that question, a plant of A. annua was grown in an atmosphere containing 700 ppm of 13CO2 for 100 min. Following a chase period of 10 days, artemisinin was isolated and analyzed by 13C NMR spectroscopy. The isotopologue pattern shows that artemisinin was predominantly biosynthesized from (E,E)-farnesyl diphosphate (FPP) whose central isoprenoid unit had been obtained via the non-mevalonate pathway. The isotopologue data confirm the previously proposed mechanisms for the cyclization of (E,E)-FPP to amorphadiene and its oxidative conversion to artemisinin. They also support deprotonation of a terminal allyl cation intermediate as the final step in the enzymatic conversion of FPP to amorphadiene and show that either of the two methyl groups can undergo deprotonation. 相似文献
135.
Birgit Riepl Susanne Grässel Reiner Wiest Martin Fleck Rainer H Straub 《Arthritis research & therapy》2010,12(3):R110
Introduction
Neutrophils and monocytes play an important role in overt inflammation in chronic inflammatory joint diseases such as rheumatoid arthritis (RA). The sympathetic nervous system (SNS) inhibits many neutrophil/monocyte functions and macrophage tumor necrosis factor (TNF), but because of the loss of sympathetic nerve fibers in inflamed tissue, sympathetic control is attenuated. In this study, we focused on noradrenergic and TNF regulation of human neutrophil peptides 1-3 (HNP1-3), which are proinflammatory bactericidal α-defensins. 相似文献136.
Two different lantibiotic-like peptides originate from the ericin gene cluster of Bacillus subtilis A1/3 总被引:7,自引:0,他引:7 下载免费PDF全文
Stein T Borchert S Conrad B Feesche J Hofemeister B Hofemeister J Entian KD 《Journal of bacteriology》2002,184(6):1703-1711
A lantibiotic gene cluster was identified in Bacillus subtilis A1/3 showing a high degree of homology to the subtilin gene cluster and occupying the same genetic locus as the spa genes in B. subtilis ATCC 6633. The gene cluster exhibits diversity with respect to duplication of two subtilin-like genes which are separated by a sequence similar to a portion of a lanC gene. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analyses of B. subtilis A1/3 culture extracts confirmed the presence of two lantibiotic-like peptides, ericin S (3,442 Da) and ericin A (2,986 Da). Disruption of the lanB-homologous gene eriB resulted in loss of production of both peptides, demonstrating that they are processed in an eriB-dependent manner. Although precursors of ericins S and A show only 75% of identity, the matured lantibiotic-like peptides reveal highly similar physical properties; separation was only achieved after multistep, reversed-phase high-performance liquid chromatography. Based on Edman and peptidase degradation in combination with MALDI-TOF MS, for ericin S a subtilin-like, lanthionine-bridging pattern is supposed. For ericin A two C-terminal rings are different from the lanthionine pattern of subtilin. Due to only four amino acid exchanges, ericin S and subtilin revealed similar antibiotic activities as well as similar properties in response to heat and protease treatment. For ericin A only minor antibiotic activity was found. 相似文献
137.
Lends Alons Berbon Mélanie Habenstein Birgit Nishiyama Yusuke Loquet Antoine 《Journal of biomolecular NMR》2021,75(10-12):417-427
Journal of Biomolecular NMR - Solid-state NMR spectroscopy is a powerful technique to study insoluble and non-crystalline proteins and protein complexes at atomic resolution. The development of... 相似文献
138.
Stéphane Compant Marine C. Cambon Corinne Vacher Birgit Mitter Abdul Samad Angela Sessitsch 《Environmental microbiology》2021,23(4):1812-1829
The plant endosphere is colonized by complex microbial communities and microorganisms, which colonize the plant interior at least part of their lifetime and are termed endophytes. Their functions range from mutualism to pathogenicity. All plant organs and tissues are generally colonized by bacterial endophytes and their diversity and composition depend on the plant, the plant organ and its physiological conditions, the plant growth stage as well as on the environment. Plant-associated microorganisms, and in particular endophytes, have lately received high attention, because of the increasing awareness of the importance of host-associated microbiota for the functioning and performance of their host. Some endophyte functions are known from mostly lab assays, genome prediction and few metagenome analyses; however, we have limited understanding on in planta activities, particularly considering the diversity of micro-environments and the dynamics of conditions. In our review, we present recent findings on endosphere environments, their physiological conditions and endophyte colonization. Furthermore, we discuss microbial functions, the interaction between endophytes and plants as well as methodological limitations of endophyte research. We also provide an outlook on needs of future research to improve our understanding on the role of microbiota colonizing the endosphere on plant traits and ecosystem functioning. 相似文献
139.
Peter A. Davey Anne Marie Power Romana Santos Philip Bertemes Peter Ladurner Pawel Palmowski Jessica Clarke Patrick Flammang Birgit Lengerer Elise Hennebert Ute Rothbächer Robert Pjeta Julia Wunderer Michal Zurovec Nick Aldred 《Biological reviews of the Cambridge Philosophical Society》2021,96(3):1051-1075
Many aquatic invertebrates are associated with surfaces, using adhesives to attach to the substratum for locomotion, prey capture, reproduction, building or defence. Their intriguing and sophisticated biological glues have been the focus of study for decades. In all but a couple of specific taxa, however, the precise mechanisms by which the bioadhesives stick to surfaces underwater and (in many cases) harden have proved to be elusive. Since the bulk components are known to be based on proteins in most organisms, the opportunities provided by advancing ‘omics technologies have revolutionised bioadhesion research. Time-consuming isolation and analysis of single molecules has been either replaced or augmented by the generation of massive data sets that describe the organism's translated genes and proteins. While these new approaches have provided resources and opportunities that have enabled physiological insights and taxonomic comparisons that were not previously possible, they do not provide the complete picture and continued multi-disciplinarity is essential. This review covers the various ways in which ‘omics have contributed to our understanding of adhesion by aquatic invertebrates, with new data to illustrate key points. The associated challenges are highlighted and priorities are suggested for future research. 相似文献