NMR and circular dichroism studies of synthetic peptides derived from the third intracellular loop of the β-adrenoceptor

AbstractThe C-terminal part of the third intracellular loop of the β-adrenoceptor is capable of stimulating adenylate cyclase in the presence of phospholipid vesicles via the stimulatory guanine nucleotide binding protein (Gs) [Palm et al. (1989) FEBS Lett. 254, 89–93]. We have investigated the structure of synthetic peptides corresponding to residues 284–295 of the turkey erythrocyte adrenoceptor in micelles, trifluoroethanol and aqueous solution, by using 2D 1H NMR and CD. In the presence of phospholipid micelles the peptides display a C-terminal α-helical region, whereas the N-terminal part was found to be highly flexible

The genome of the square archaeon Haloquadratum walsbyi : life at the limits of water activity

BACKGROUND: The square halophilic archaeon Haloquadratum walsbyi dominates NaCl-saturated and MgCl(2 )enriched aquatic ecosystems, which imposes a serious desiccation stress, caused by the extremely low water activity. The genome sequence was analyzed and physiological and physical experiments were carried out in order to reveal how H. walsbyi has specialized into its narrow and hostile ecological niche and found ways to cope with the desiccation stress. RESULTS: A rich repertoire of proteins involved in phosphate metabolism, phototrophic growth and extracellular protective polymers, including the largest archaeal protein (9159 amino acids), a homolog to eukaryotic mucins, are amongst the most outstanding features. A relatively low GC content (47.9%), 15–20% less than in other halophilic archaea, and one of the lowest coding densities (76.5%) known for prokaryotes might be an indication for the specialization in its unique environment CONCLUSION: Although no direct genetic indication was found that can explain how this peculiar organism retains its square shape, the genome revealed several unique adaptive traits that allow this organism to thrive in its specific and extreme niche

Haloquadratum walsbyi : Limited Diversity in a Global Pond

BACKGROUND: Haloquadratum walsbyi commonly dominates the microbial flora of hypersaline waters. Its cells are extremely fragile squares requiring >14%(w/v) salt for growth, properties that should limit its dispersal and promote geographical isolation and divergence. To assess this, the genome sequences of two isolates recovered from sites at near maximum distance on Earth, were compared. PRINCIPAL FINDINGS: Both chromosomes are 3.1 MB in size, and 84% of each sequence was highly similar to the other (98.6% identity), comprising the core sequence. ORFs of this shared sequence were completely synteneic (conserved in genomic orientation and order), without inversion or rearrangement. Strain-specific insertions/deletions could be precisely mapped, often allowing the genetic events to be inferred. Many inferred deletions were associated with short direct repeats (4-20 bp). Deletion-coupled insertions are frequent, producing different sequences at identical positions. In cases where the inserted and deleted sequences are homologous, this leads to variant genes in a common synteneic background (as already described by others). Cas/CRISPR systems are present in C23(T) but have been lost in HBSQ001 except for a few spacer remnants. Numerous types of mobile genetic elements occur in both strains, most of which appear to be active, and with some specifically targetting others. Strain C23(T) carries two ∼6 kb plasmids that show similarity to halovirus His1 and to sequences nearby halovirus/plasmid gene clusters commonly found in haloarchaea. CONCLUSIONS: Deletion-coupled insertions show that Hqr. walsbyi evolves by uptake and precise integration of foreign DNA, probably originating from close relatives. Change is also driven by mobile genetic elements but these do not by themselves explain the atypically low gene coding density found in this species. The remarkable genome conservation despite the presence of active systems for genome rearrangement implies both an efficient global dispersal system, and a high selective fitness for this species

Monitoring of total copper contents in organically and conventionally managed soils. Part 4: – Total contents in German pomiculture soils

Die Auswirkungen dauerhafter Anwendung kupferhaltiger Fungizide auf die Nachhaltigkeit der Bodengüte sind im Rahmen der Europäischen Wirkstoffzulassung Gegenstand eines EU-weiten Programms zur Erfassung der Kupfer­gehalte im Boden geworden. 1613 Einzelproben wurden aus den Bodenhorizonten 0–5 und 5–20 cm von Baumobstlagen an 40 ökologisch und 12 konventionell bewirtschafteten Standorten unter den Aspekten einer möglichst repräsentativen Erfassung der Belastungsverteilung entnommen. Das Erhebungs­ergebnis soll als Grundlage für die Auswahl gebietstypischer Anbausituationen dienen, die in Verbindung mit einer spezifischen Expositionsermittlung die Erfassung der Wirkungsausprägung an empfindlichen Indikator­arten der jeweiligen Regenwurmzönosen ermöglicht. Auf der Basis von Gesamtgehalten wird die Belastungssituation und -verteilung auf Prüfflächen und Referenzflächen in deutschen Baumobstbaugebieten als Minimal-, Mittel- und Maximalwert sowie für verschiedene Perzentile dargestellt. Darüber hinaus werden aus der Bewirtschaftungshistorie resultierende Schwermetallein­träge quantifiziert und Belastungsunterschiede zwischen Obstbaumreihen und Fahrgassen diskutiert. Bei der Belastungserhebung konnte durch Verknüpfung von Daten zur Bewirtschaftungsgeschichte mit vorhandenen Flächenbelastungen in Verbindung mit beispielhaft für das Anbaugebiet Niederelbe ermittelten Kupferaufwandmengen im Zeitraum 1960 bis 2010 nachgewiesen werden, dass diese Belastungen aus den Jahren 1960 bis etwa 1995 resultieren, wo noch zwischen 10 und 13 kg Reinkupfer pro Jahr und Hektar zur Schaderregerbekämpfung im Baumobstbau angewandt wurden. Welche Anteile von diesen ‚gealterten’ Kupfergesamtgehalten bioverfügbar sind und damit auf die Bodenzönose wirken, wird derzeit untersucht. Anhand der in der Vorbeprobung erhobenen Daten zur Belastungssituation, Standortbeschreibung und Bewirtschaftungsdauer werden 2 bis 3 Baumobstlagen vorgeschlagen, die sich für eine biologische Statuserhebung zu Auswirkungen auf die Regenwurmzönose eignen.    Implications of long-term usage of copper fungicides on sustainable soil quality have been described for a long time, and according to the regulation of active substances, are objective of a survey on copper contents in agricultural soils in several EU member countries. 1613 single samples from the soil horizon 0–5 and 5–20 cm were taken from 40 organically and 12 conventionally managed pomiculture sites trying to make reference to all aspects relevant for a representative assessment of copper loads. The result of that survey is intended to enable the selection of site-typical types of cultivation being the prerequisite of an assessment of effects to the earthworm coenosis in combination with a refined exposure analysis. On the basis of total contents, the copper load and their distribution on test and reference fields of German pomiculture cultivation sites is presented including the minimum, maximum and mean value as well as percentiles. Additionally, the heavy metal content in general was determined and differences in copper contents between tree row and driving lines were identified. Comparing managing history and current management, it is obvious that load peaks result from copper applications between 1960 to 1995, when between 10 to 13 kg copper per ha and year were applied to control plant diseases. The evaluation of bio available copper, resulting from aged total copper contents, is not yet completely finished. By means of data, generated in preliminary samplings concerning load situation, site description and duration of management, 2–3 pomiculture sites are suggested being appropriate to assess the recent situation of soil quality in terms of responses on a population level.   &nbsp

Relative efficiency of non parametric error rate estimators in multi-group linear discriminant analysis

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