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I. A. Bass Zh. M. Gorlenko O. N. Danilevskaya A. D. Dmitriev E. S. Kalyaeva S. Z. Mindlin A. V. Timopheev R. S. Khesin 《Molecular & general genetics : MGG》1977,154(1):101-110
Summary In merodiploid cells containing a double dose of structural genes of RNA polymerase subunits-rpoBand rpoC-the rate of and subunits synthesis is 2 times higher than in haploidcells. Missence mutation rpoC1 (tsX) alters polypeptide and inducesthe and subunits synthesis at increased rate, particularly at a nonpermissive temperature. When rpoBCoperon carrying mutation rpoC1 is duplicated no dosage effect is observed. In the rpoC
+/rpoC1 heterodiploid the rpoC1 mutation does not significantly accelerate RNA polymerase subunits synthesis i.e. is recessive with respect to rpoC
+
Rifampicin causes 6-fold stimulation of RNA polymerase subunits synthesis in a sensitive wild-type strain. The rpoC1 mutation itself accelerates the synthesis of these subunits 3-fold. In the presence of rifampicin the mutant strain produces 13–22-fold faster as compared to wild-type strain without the drug. Thus, the effects of rifampicin and the mutation are multiplied suggesting that these factors act independently. Similar data have also been obtained with rifampicin-treated cells of rpoB22 (ts22) amber-mutant.After UV-irradiation of cells and synthesis is depressed much stronger than the total protein synthesis. Infection with a transducing phage rif
d-47 which carries rpoB gene provokes a higher rate of synthesis. When pre-irradiated cells (500 erg/mm2) are infected with this phage, the rate of synthesis grows 20-fold compared to irradiated, non-infected cells and 6.5-fold compared to intact cells.The data are discussed in terms of the possible regulatory mechanisms of RNA polymerase subunit synthesis. 相似文献
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Craig M. Richael Marina Kalyaeva Robert C. Chretien Hua Yan Sathya Adimulam Artesia Stivison J. Troy Weeks Caius M. Rommens 《Transgenic research》2008,17(5):905-917
Conventional Agrobacterium-mediated transformation methods rely on complex and genotype-specific tissue culture media for selection, proliferation, and regeneration of genetically modified cells. Resulting transgenic plants may not only contain selectable marker genes but also carry fragments of the vector backbone. Here, we describe a new method for the production of transgenic plants that lack such foreign DNA. This method employs vectors containing the bacterial isopentenyltransferase (ipt) gene as backbone integration marker. Agrobacterium strains carrying the resulting ipt gene-containing "cytokinin" vectors were used to infect explants of various Solanaceous plant species as well as canola (Brassica napus). Upon transfer to hormone-free media, 1.8% to 9.9% of the infected explants produced shoots that contained a marker-free T-DNA while lacking the backbone integration marker. These frequencies often equal or exceed those for backbone-free conventional transformation. 相似文献
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Reduction of protease inhibitor activity by expression of a mutant Bowman-Birk gene in soybean seed 总被引:1,自引:0,他引:1
Livingstone D Beilinson V Kalyaeva M Schmidt MA Herman EM Nielsen NC 《Plant molecular biology》2007,64(4):397-408
A mutant Bowman-Birk gene was created that encoded an inactive high-sulfur product. It was used to transform soybean line
Asgrow 3237. Transformants bearing the mutant gene were identified by GUS expression, PCR analysis, and Southern analysis.
The amount of steady state mRNA from the mutant gene in the transformed plants showed that the gene was highly expressed,
but the amount of message from the unmodified Bowman-Birk gene did not change detectably. Proteins synthesized at the direction
of the mutant Bowman-Birk gene accumulated in seeds of the transformed plants, and there was a marked decrease in the ability
of extracts prepared from these seeds to inhibit trypsin and chymotrypsin despite the presence of Kunitz trypsin inhibitor.
The more prevalent mRNA from the mutant gene was considered to out-compete message from the native genes to decrease the amount
of active Bowman-Birk inhibitor. 相似文献
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Amy C. Morrison Brett M. Forshey Desiree Notyce Helvio Astete Victor Lopez Claudio Rocha Rebecca Carrion Cristhiam Carey Dominique Eza Joel M. Montgomery Tadeusz J. Kochel 《PLoS neglected tropical diseases》2008,2(12)
Enzootic strains of Venezuelan equine encephalitis virus (VEEV) have been isolated from febrile patients in the Peruvian Amazon Basin at low but consistent levels since the early 1990s. Through a clinic-based febrile surveillance program, we detected an outbreak of VEEV infections in Iquitos, Peru, in the first half of 2006. The majority of these patients resided within urban areas of Iquitos, with no report of recent travel outside the city. To characterize the risk factors for VEEV infection within the city, an antibody prevalence study was carried out in a geographically stratified sample of urban areas of Iquitos. Additionally, entomological surveys were conducted to determine if previously incriminated vectors of enzootic VEEV were present within the city. We found that greater than 23% of Iquitos residents carried neutralizing antibodies against VEEV, with significant associations between increased antibody prevalence and age, occupation, mosquito net use, and overnight travel. Furthermore, potential vector mosquitoes were widely distributed across the city. Our results suggest that while VEEV infection is more common in rural areas, transmission also occurs within urban areas of Iquitos, and that further studies are warranted to identify the precise vectors and reservoirs involved in urban VEEV transmission. 相似文献
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Kalyaeva M. A. Zacharchenko N. S. Doronina N. V. Rukavtsova E. B. Ivanova E. G. Alekseeva V. V. Trotsenko Yu. A. Bur'yanov Ya. I. 《Russian Journal of Plant Physiology》2001,48(4):514-517
The effects of aerobic methylotrophic bacteria Methylovorus mayson growth and morphogenesis were studied in in vitropropagated tobacco, potato, and flax. Colonization of plant explants with the methylo-trophic bacteria led to the stable association of bacteria and plants and enhanced the growth and the capacity of the latter for regeneration and root formation. When colonized by the methylotrophic bacteria, the rootless transgenic tobacco plants carrying the agrobacterial cytokinin gene iptrestored their ability to form roots. These data indicate the possibility to employ methylotrophic bacteria as a tool in experimental biology and plant biotechnology. 相似文献
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We have analyzed the interaction of monoclonal antibodies against Escherichia coli RNA polymerase with products of its limited proteolysis. Two major proteolytic fragments of molecular masses 107 and 43 kDa originate as a result of a single cleavage in the vicinity of the 980th amino acid residue. Anti-beta subunit monoclonal antibody PYN-2 inhibiting RNA polymerase activity at the stage of RNA elongation reacts with an epitope located between the amino-terminus and the 50th amino acid residue of the beta subunit. DNA sequencing has shown that the RNA polymerase mutation rpoB22 converts the Gln(1111) codon of the beta subunit gene into the amber codon. An epitope for the monoclonal antibody PYN-6 was located between the major site of proteolytic cleavage and Gln(1111) of the beta subunit. 相似文献
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Summary Cold sensitive (cs) mutants of E. coli unable to grow at 26° C were isolated. Three of about 200 mutants tested have RNA polymerase which is about 5 times less active at low temperatures than the wild type RNA polymerase. One of such mutants cs 1 was studied in more detail. The mutation affects core enzyme and is closely linked to rif-r mutations. By transduction analysis the following order of markers was established: argH — rif-r — cs 1. 相似文献
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