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1.
This paper deals with the genus Dina of the Erpobdellidae. A comprehensive comparison of all known species of this genus is given. A lectotype for Dina absoloni Johansson, 1913, is selected. A new species, Dina latestriata n. sp. from Prespa Lake in Greece is described. Data concerning the evolution of Dina are given. 相似文献
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Claudio Gualerzi Michele Grandolfo Hasko H. Paradies Cynthia Pon 《Journal of molecular biology》1975,95(4):569-573
The circular dichroism spectra of Escherichia coli 30 S ribosomal subunits have been determined between 200 and 320 nm in the presence and in the absence of initiation factor IF-3. The addition of IF-3 did not produce any major alteration of the circular dichroism spectrum of the 30 S subunits between 320 and 240 nm, but resulted in an increase of the negative ellipticity between 240 and 205 nm. The effect was maximal for an IF-3:30 S molar ratio of approximately one, and further addition of IF-3 did not lead to a further increase of ellipticity. A similar effect was not seen when the 30 S ribosomal subunits were previously heat-inactivated to destroy their IF-3 binding capacity. These data indicate that the ribosomal binding of IF-3 may be accompanied by an increase in the secondary structure of the ribosomal proteins, but does not involve any major net change in the secondary structure of the rRNA. 相似文献
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Lüder Göke Hasko Paradies Günther Werz 《Biochemical and biophysical research communications》1974,60(1):22-27
The amino acid composition of stalk and cap cell wall polypeptides of the unicellular alga has been investigated. In spite of chemical and physical differences between stalk and can cell wall polysaccharides, the amino acid composition of the cell wall polypeptides appeared qualitatively similar in both structures. however, quantitative differences have been observed. The results are discussed on the basis of a possible role of the polypeptides in the growth of the cell wall. 相似文献
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Brigitte Zimmer H. Hasko Paradies Günther Werz 《Biochemical and biophysical research communications》1977,74(4):1496-1500
Crystals of D-ribulose-1,5-biphosphate carboxylase (E.C. 4.1.1.39), naturally occurring in the extraplasmatic space of the unicellular green algae (Dasycladaceae), were studied by means of electron microscopy and optical diffraction. Optical diffraction patterns were obtained from thin sections. It is shown that the crystals are composed of cubic unit cells with α ~ 31.5 nm. The density of the crystals was estimated as 1.07 ± 0.005 g/ml, a value that gives evidence of the presence of 12 enzyme molecules per unit cell. Optical diffraction studies of the thin sectioned crystals revealed 4mm -symmetry with four 2-fold rotation axes, resulting in at least a 222-symmetry. 相似文献
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H.Hasko Paradies Brigitte Zimmer Günther Werz 《Biochemical and biophysical research communications》1977,74(2):397-404
D-Ribulose-1,5-diphosphate carboxylase from was purified, and the gross dimensions were obtained by means of small-angle X-ray scattering measurements in solution. Dissolved single crystals of this enzyme (called “fraction I protein”) gave the same hydrodynamic parameters as the purified form. The molecular weight was found to be 535,000, and a radius of gyration of Rg = 45.5 Å was determined. The experimental scattering curves revealed a geometrical particle of D-Ribulose-1,5-diphosphate carboxylase with gross dimensions of that of a hollow sphere with outer radius of 56 Å and inner radius of 12 Å. Determinations of the diffusion coefficients lead to the conclusion that the enzyme has a spherical shape of almost uniform density. 相似文献
8.
Lorenzo Cecchi Roberto Gabbrielli Miluscia Arnetoli Cristina Gonnelli Agim Hasko Federico Selvi 《Annals of botany》2010,106(5):751-767
Background and Aims
Nickel (Ni) hyperaccumulation is a rare form of physiological specialization shared by a small number of angiosperms growing on ultramafic soils. The evolutionary patterns of this feature among European members of tribe Alysseae (Brassicaceae) are investigated using a phylogenetic approach to assess relationships among Ni hyperaccumulators at the genus, species and below-species level.Methods
Internal transcribed spacer (ITS) sequences were generated for multiple accessions of Alysseae. Phylogenetic trees were obtained for the genera of the tribe and Alyssum sect. Odontarrhena. All accessions and additional herbarium material were tested for Ni hyperaccumulation with the dimethylglyoxime colorimetric method.Key Results
Molecular data strongly support the poorly known hyperaccumulator endemic Leptoplax (Peltaria) emarginata as sister to hyperaccumulator species of Bornmuellera within Alysseae. This is contrary to current assumptions of affinity between L. emarginata and the non-hyperaccumulator Peltaria in Thlaspideae. The lineage Bornmuellera–Leptoplax is, in turn, sister to the two non-hyperaccumulator Mediterranean endemics Ptilotrichum rupestre and P. cyclocarpum. Low ITS sequence variation was found within the monophyletic Alyssum sect. Odontarrhena and especially in A. murale sensu lato. Nickel hyperaccumulation was not monophyletic in any of three main clades retrieved, each consisting of hyperaccumulators and non-hyperaccumulators of different geographical origin.Conclusions
Nickel hyperaccumulation in Alysseae has a double origin, but it did not evolve in Thlaspideae. In Bornmuellera–Leptoplax it represents an early synapomorphy inherited from an ancestor shared with the calcicolous, sister clade of Mediterranean Ptilotrichum. In Alyssum sect. Odontarrhena it has multiple origins even within the three European clades recognized. Lack of geographical cohesion suggests that accumulation ability has been lost or gained over the different serpentine areas of south Europe through independent events of microevolutionary adaptation and selection. Genetic continuity and strong phenotypic plasticity in the A. murale complex call for a reduction of the number of Ni hyperaccumulator taxa formally recognized. 相似文献9.
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Nesemann Kai Braus-Stromeyer Susanna A. Harting Rebekka Höfer Annalena Kusch Harald Ambrosio Alinne Batista Timpner Christian Braus Gerhard H. 《Applied microbiology and biotechnology》2018,102(2):817-831
Applied Microbiology and Biotechnology - Verticillium species represent economically important phytopathogenic fungi with bacteria as natural rhizosphere antagonists. Growth inhibition patterns of... 相似文献