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871.
Itoic Acid Synthesis in Bacillus subtilis 总被引:8,自引:5,他引:3
Under conditions of iron deficiency, strains of Bacillus subtilis produced 2,3-dihydroxybenzoic acid (DHB), 2,3-dihydroxybenzolyglycine (DHBG), or both of these compounds. DHB(G) production [production of DHB(G) refers to the production of DHB, or DHBG, or both] was proportional to the amount of iron present and occurred logarithmically, paralleling growth. Supplementation of media with more than 150 mug of iron per liter at zero-time inhibited DHB accumulation completely. In the presence of DHB, lower levels of iron inhibited DHB(G) production, so that the actual inhibitor of synthesis may involve the Fe(3+):[DHB(G)](3) complex. The strains producing DHBG also produced coproporphyrin III during iron-deficient growth, whereas a strain producing DHB did not produce coproporphyrin III under these conditions. Accumulation of DHB(G) was influenced by the levels of aromatic amino acids and anthranilic acid in the medium. In vivo experiments with strain B-1471 demonstrated that DHB was coupled to added glycine to form DHBG. Metabolism of DHB(G) was observed in two of the strains studied. 相似文献
872.
Zusammenfassung Es wird aufgezeigt, da\ der aufDarwin selbst zurückgehende eingeengte Gebrauch des Selektionskonzeptes auf die Beziehung zwischen Organismus und Umwelt die biologische Konstruktion der vorphylogenetischen idealistischen Morphologie überlassen hat. Ein zutreffendes VerstÄndnis des Evolutionsmechanismus begreift aber die biologische Apparatur ein, entzieht der Morphologie, soweit sie sich als Vorbedingung phylogenetischen Arbeitens versteht, den Boden.
Summary It is argued that the narrow concept of selection used since the time ofDarwin is only concerned with the relation between organism and its environment (niche). It did not include the organism itself, which was the object of the pre-phylogenetic idealistic morphology. An adequate understanding of the mechanism of evolution dispenses with the concept of morphology as the basis of phylogeny.相似文献
873.
Meyer Engel E. Stein Lüers P. Sabaneeff Lein G. Kretschmer M. Zwintzscher H. J. Müller H. Nachtsheim St. Reichmuth Wulff J. Straub I. Grebenščikov K. Paech M. Oesterlin Dielzel U. Ruge F. Moewus K. Peters Erb.-Lanz G. Bosian W. Rothmaler 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1951,21(4-5):153-160
Ohne Zusammenfassung 相似文献
874.
John Peters 《The Western journal of medicine》1953,78(4):274-276
So-called “minor psychiatry,” the treatment of neurosis in persons who are not psychotic, may well be undertaken by the general practitioner.The first duty of the physician in dealing with a neurotic person is to determine whether psychosis may develop. He must be patient and thorough in hearing the history of the case and should have full information on the patient''s life and family.A recent classification of the neuroses is given and the more generally recognized symptoms of these conditions are described. 相似文献
875.
Walther Hoffmann Ruth Peters 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1958,28(1):40-51
Ohne ZusammenfassungMit 7 AbbildungenHerrn Prof. Dr. R.v.Sengbusch zu seinem 60. Geburtstag gewidmet. 相似文献
876.
877.
878.
879.
880.
Michael W. Ris?r Line R. Thomsen Kristian W. Sanggaard Tania A. Nielsen Ida B. Th?gersen Marie V. Lukassen Litten Rossen Irene Garcia-Ferrer Tibisay Guevara Carsten Scavenius Ernst Meinjohanns F. Xavier Gomis-Rüth Jan J. Enghild 《The Journal of biological chemistry》2016,291(5):2271-2287
Carnivorous plants primarily use aspartic proteases during digestion of captured prey. In contrast, the major endopeptidases in the digestive fluid of the Venus flytrap (Dionaea muscipula) are cysteine proteases (dionain-1 to -4). Here, we present the crystal structure of mature dionain-1 in covalent complex with inhibitor E-64 at 1.5 Å resolution. The enzyme exhibits an overall protein fold reminiscent of other plant cysteine proteases. The inactive glycosylated pro-form undergoes autoprocessing and self-activation, optimally at the physiologically relevant pH value of 3.6, at which the protective effect of the pro-domain is lost. The mature enzyme was able to efficiently degrade a Drosophila fly protein extract at pH 4 showing high activity against the abundant Lys- and Arg-rich protein, myosin. The substrate specificity of dionain-1 was largely similar to that of papain with a preference for hydrophobic and aliphatic residues in subsite S2 and for positively charged residues in S1. A tentative structure of the pro-domain was obtained by homology modeling and suggested that a pro-peptide Lys residue intrudes into the S2 pocket, which is more spacious than in papain. This study provides the first analysis of a cysteine protease from the digestive fluid of a carnivorous plant and confirms the close relationship between carnivorous action and plant defense mechanisms. 相似文献