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Transduction of genetic markers conferring drug-resistance with lambda phagemids has been studied in terms of the influence of various genetic conditions on the level of transduction. For this purpose, we have constructed and analysed a new series of phagemids - lambda gt::pBR322 and lambda gt::pUC19, in addition to earlier published phagemids. Experimental data indicate that the transduction frequency depends on the function of cI repressor and bacterial recA system, the plasmid orientation in the phagemid DNA, the selective marker used in an experiment and the concentration of the antibiotic in the medium. 相似文献
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Christiane Dahl Gábor Rákhely A.S. Pott-Sperling Barna Fodor Mária Takács rás Tóth Monika Kraeling Krisztina Gyrfi Ákos Kovács Jennifer Tusz Kornél L. Kovács 《FEMS microbiology letters》1999,180(2):317-324
The dsr genes and the hydSL operon are present as separate entities in phototrophic sulfur oxidizers of the genera Allochromatium, Marichromatium, Thiocapsa and Thiocystis and are organized similarly as in Allochromatium vinosum and Thiocapsa roseopersicina, respectively. The dsrA gene, encoding the alpha subunit of 'reverse' siroheme sulfite reductase, is also present in two species of green sulfur bacteria pointing to an important and universal role of this enzyme and probably other proteins encoded in the dsr locus in the oxidation of stored sulfur by phototrophic bacteria. The hupSL genes are uniformly present in the members of the Chromatiaceae family tested. The two genes between hydS and hydL encode a membrane-bound b-type cytochrome and a soluble iron-sulfur protein, respectively, resembling subunits of heterodisulfide reductase from methanogenic archaea. These genes are similar but not identical to dsrM and dsrK, indicating that the derived proteins have distinct functions, the former in hydrogen metabolism and the latter in oxidative sulfur metabolism. 相似文献
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V I Krauzova T N Kopylova-Sviridova T M Timiriasova I I Fodor 《Molekuliarnaia genetika, mikrobiologiia i virusologiia》1991,(2):23-28
The transient expression of the two reporter genes, the genes for luciferase and bacterial beta-galactosidase, were used for comparative estimation of vaccinia viral promoters and for characterizing of the constructed plasmids. The recombinant clones of vaccinia virus expressing simultaneously and with high efficiency the luciferase and beta-galactosidase were used for studying the reproduction of vaccinia virus in mammalian cells. The advantages of the luciferase gene in using it as a reporter gene are discussed. 相似文献