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Role of DNA methyltransferases in regulation of human ribosomal RNA gene transcription 总被引:5,自引:0,他引:5
Majumder S Ghoshal K Datta J Smith DS Bai S Jacob ST 《The Journal of biological chemistry》2006,281(31):22062-22072
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Initiation and regulation mechanisms of ribosomal RNA transcription in the eukaryote Acanthamoeba castellanii 总被引:1,自引:0,他引:1
Marvin R. Paule Erik Bateman Laura Hoffman Calvin Iida Martin Imboden William Kubaska Preecha Kownin Han Li Alan Lofquist Peggy Risi Qin Yang Michael Zwick 《Molecular and cellular biochemistry》1991,104(1-2):119-126
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The Borrelia burgdorferi outer surface lipoprotein OspA is a current focus for vaccine development to prevent Lyme disease infection. A soluble, recombinant form of the protein lacking the aminoterminal lipid membrane anchor was cocrystallized with the Fab fragment of an agglutinating mouse monoclonal antibody. The crystals belong to space group P212121, with a = 90.0 Å, b = 91.9 Å, and c = 102.9 Å and they were found to diffract to a maximum resolution of 2.8 Å using synchrotron radiation. 相似文献
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Patterns of ribosomal RNA evolution in salamanders 总被引:4,自引:0,他引:4
Sequence comparisons are presented for four segments of the large subunit
of ribosomal RNA, including divergent domains D7a and D7b, portions of the
large divergent domains D2, D3, and D8, and evolutionarily conservative
sequences flanking divergent domains. These results resolve phylogenetic
relationships among exemplars of seven families of salamanders and the
three amphibian orders. Phylogenetic analysis confirms the prediction that
divergent domains feature the highest relative rates of base substitution
and length variation within the ribosome, but the divergent domains evolve
more slowly than nuclear noncoding DNA and the silent sites of structural
genes. Base substitutions demonstrate approximately twice as many
transitions as transversions and an uneven distribution among sites within
the divergent domains but no apparent bias in base composition. Length
mutations are primarily small insertions and deletions, with deletions
predominating. The divergent domains appear to be a good source of
phylogenetic information for evolutionary events occurring approximately
100-200 million years ago.
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Akira Muto 《Molecular & general genetics : MGG》1977,152(2):153-159
Summary The ribosomal RNA synthesis in a cell-free system containing the nucleoids and the cytoplasmic fraction prepared from Escherichia coli cells has been investigated. The addition of the 4S fraction from the cytoplasm to the isolated nucleoids induces RNA synthesis by a new chain initiation. In this system a preferential initiation of rRNA chains occurs. The experimental results suggest that the 4S fraction contains at least two activities, one for releasing RNA-polymerases from the nucleoids, and another for the frequent initiation of rRNA chains. No restriction of the rRNA synthesis has been observed in the nucleoids and the 4S fraction from the amino acidstarved rel
+ cells. The rRNA synthesized in the above system is detected at about 23S and 16S rRNA regions. 相似文献
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Makoto Sawada Akira Muto Masafumi Iwami Fumiaki Yamao Syozo Osawa 《Molecular & general genetics : MGG》1984,196(2):311-316
Summary DNA segments carrying rRNA genes of Mycoplasma capricolum have been cloned and characterized by restriction endonuclease mapping, DNA-RNA hybridization and nucleotide sequencing. The M. capricolum genome has two sets of rRNA gene clusters, where the arrangement is in the order of (5)16S-23S-5S(3). The spacer region between 16S and 23S rDNA is extremely rich in AT and does not carry any tRNA genes.
Present address: Division of Hematology and Immunology of Internal Medicine, Kanazawa Medical University, Uchinada-Cho, Kahoku-Gun Ishikawa Pref. 920-02, Japan 相似文献
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Promoter occlusion during ribosomal RNA transcription 总被引:34,自引:0,他引:34
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Andrew Travers 《Cell》1976,8(4):605-609
The rate of rRNA synthesis from E. coli DNA in vitro can exhibit an unusual temperature dependence. Instead of the typical sigmoid curve, at least five to six pronounced peaks of rRNA synthesis are detectable over a 30° range in temperature. rRNA synthesis from preformed initiation complexes exhibits a similar pattern and shows that the number of polymerases able to initiate rRNA synthesis increases with each successive peak. These results are interpreted in terms of a model which proposes that the rRNA cistrons are served by multiple promoter sites (subpromoters) whose activation energies form a graded series. Thus the number of polymerases initiating rRNA synthesis could be controlled by regulating the number of active subpromoters. 相似文献
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Dictyostelium ribosomal RNA is processed during transcription 总被引:1,自引:0,他引:1
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Summary Slow-growing mutants were isolated after mutagenesis of the osmotic-sensitive strain Saccharomyces cerevisiae VY1160. The isolated mutants in rich media have generation times from 300 to 400 min at 30°C. Studies on the biosynthesis of rRNAx have shown, that the processing of 37S pre-rRNA in 6 of the slow-growing mutants occurs 3 to 4 times slower than in the parental strain. These mutants with decreased rate of rRNA maturation are of two different types. In some of them the processing of both 37S and 27S pre-rRNA is slowed down, while the mutants from the second group are acharacterized by a specific inhibition of the step 27S pre-rRNA25S rRNA. Experiments in which the synthesis of macromolecules was studied, have shown that in the mutants and in the parental strain, RNA and proteins are synthesized at comparable rates. Preliminary results suggest that the decreased rate of rRNA processing in three of the isolated mutants might be due to an insufficient function of the enzymes involved in the maturation of rRNA.Abbreviations rRNA
ribosomal RNA
- pre-rRNA
precursor to ribosomal RNA 相似文献