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Academic literature on the topic 'Operoni'
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Journal articles on the topic "Operoni"
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Nguyen, Huy N., Ashish Jain, Oliver Eulenstein, and Iddo Friedberg. "Tracing the ancestry of operons in bacteria." Bioinformatics 35, no. 17 (2019): 2998–3004. http://dx.doi.org/10.1093/bioinformatics/btz053.
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Abstract Motivation Complexity is a fundamental attribute of life. Complex systems are made of parts that together perform functions that a single component, or subsets of components, cannot. Examples of complex molecular systems include protein structures such as the F1Fo-ATPase, the ribosome, or the flagellar motor: each one of these structures requires most or all of its components to function properly. Given the ubiquity of complex systems in the biosphere, understanding the evolution of complexity is central to biology. At the molecular level, operons are classic examples of a complex system. An operon’s genes are co-transcribed under the control of a single promoter to a polycistronic mRNA molecule, and the operon’s gene products often form molecular complexes or metabolic pathways. With the large number of complete bacterial genomes available, we now have the opportunity to explore the evolution of these complex entities, by identifying possible intermediate states of operons. Results In this work, we developed a maximum parsimony algorithm to reconstruct ancestral operon states, and show a simple vertical evolution model of how operons may evolve from the individual component genes. We describe several ancestral states that are plausible functional intermediate forms leading to the full operon. We also offer Reconstruction of Ancestral Gene blocks Using Events or ROAGUE as a software tool for those interested in exploring gene block and operon evolution. Availability and implementation The software accompanying this paper is available under GPLv3 license on: https://github.com/nguyenngochuy91/Ancestral-Blocks-Reconstruction. Supplementary information Supplementary data are available at Bioinformatics online.
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Brandis, Gerrit, Sha Cao, and Diarmaid Hughes. "Operon Concatenation Is an Ancient Feature That Restricts the Potential to Rearrange Bacterial Chromosomes." Molecular Biology and Evolution 36, no. 9 (2019): 1990–2000. http://dx.doi.org/10.1093/molbev/msz129.
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Abstract The last common ancestor of the Gammaproteobacteria carried an important 40-kb chromosome section encoding 51 proteins of the transcriptional and translational machinery. These genes were organized into eight contiguous operons (rrnB-tufB-secE-rpoBC-str-S10-spc-alpha). Over 2 Gy of evolution, in different lineages, some of the operons became separated by multigene insertions. Surprisingly, in many Enterobacteriaceae, much of the ancient organization is conserved, indicating a strong selective force on the operons to remain colinear. Here, we show for one operon pair, tufB-secE in Salmonella, that an interruption of contiguity significantly reduces growth rate. Our data show that the tufB-secE operons are concatenated by an interoperon terminator–promoter overlap that plays a significant role regulating gene expression. Interrupting operon contiguity interferes with this regulation, reducing cellular fitness. Six operons of the ancestral chromosome section remain contiguous in Salmonella (tufB-secE-rpoBC and S10-spc-alpha) and, strikingly, each of these operon pairs is also connected by an interoperon terminator–promoter overlap. Accordingly, we propose that operon concatenation is an ancient feature that restricts the potential to rearrange bacterial chromosomes and can select for the maintenance of a colinear operon organization over billions of years.
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Ming, Li, and Anna Boiko. "Recipes of the Russian opera tradition in the Chinese opera art of the 20th century." OOO "Zhurnal "Voprosy Istorii" 2020, no. 11-1 (2020): 170–78. http://dx.doi.org/10.31166/voprosyistorii202011statyi07.
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The publication is devoted to the consideration of the peculiarities of the reception of Russian opera tradition in the Chinese opera of 20th century. The significant role of the historical and the cultural events that affected the spread Russian opera in China is analyzed. Particular attention is paid to the study of the activities of representatives the Russian emigration in the field of opera art. It was emphasized that the influence of Russian and foreign opera contributed to the formation of the genre the Chinese opera of the European type.
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Acinas, Silvia G., Luisa A. Marcelino, Vanja Klepac-Ceraj, and Martin F. Polz. "Divergence and Redundancy of 16S rRNA Sequences in Genomes with Multiple rrn Operons." Journal of Bacteriology 186, no. 9 (2004): 2629–35. http://dx.doi.org/10.1128/jb.186.9.2629-2635.2004.
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ABSTRACT The level of sequence heterogeneity among rrn operons within genomes determines the accuracy of diversity estimation by 16S rRNA-based methods. Furthermore, the occurrence of widespread horizontal gene transfer (HGT) between distantly related rrn operons casts doubt on reconstructions of phylogenetic relationships. For this study, patterns of distribution of rrn copy numbers, interoperonic divergence, and redundancy of 16S rRNA sequences were evaluated. Bacterial genomes display up to 15 operons and operon numbers up to 7 are commonly found, but ∼40% of the organisms analyzed have either one or two operons. Among the Archaea, a single operon appears to dominate and the highest number of operons is five. About 40% of sequences among 380 operons in 76 bacterial genomes with multiple operons were identical to at least one other 16S rRNA sequence in the same genome, and in 38% of the genomes all 16S rRNAs were invariant. For Archaea, the number of identical operons was only 25%, but only five genomes with 21 operons are currently available. These considerations suggest an upper bound of roughly threefold overestimation of bacterial diversity resulting from cloning and sequencing of 16S rRNA genes from the environment; however, the inclusion of genomes with a single rrn operon may lower this correction factor to ∼2.5. Divergence among operons appears to be small overall for both Bacteria and Archaea, with the vast majority of 16S rRNA sequences showing <1% nucleotide differences. Only five genomes with operons with a higher level of nucleotide divergence were detected, and Thermoanaerobacter tengcongensis exhibited the highest level of divergence (11.6%) noted to date. Overall, four of the five extreme cases of operon differences occurred among thermophilic bacteria, suggesting a much higher incidence of HGT in these bacteria than in other groups.
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Yap, Wai Ho, Zhenshui Zhang, and Yue Wang. "Distinct Types of rRNA Operons Exist in the Genome of the Actinomycete Thermomonospora chromogena and Evidence for Horizontal Transfer of an Entire rRNA Operon." Journal of Bacteriology 181, no. 17 (1999): 5201–9. http://dx.doi.org/10.1128/jb.181.17.5201-5209.1999.
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ABSTRACT We describe here the presence of two distinct types of rRNA operons in the genome of a thermophilic actinomycete Thermomonospora chromogena. The genome of T. chromogena contains six rRNA operons (rrn), of which four complete and two incomplete ones were cloned and sequenced. Comparative analysis revealed that the operon rrnB exhibits high levels of sequence variations to the other five nearly identical ones throughout the entire length of the operon. The coding sequences for the 16S and 23S rRNA genes differ by approximately 6 and 10%, respectively, between the two types of operons. Normal functionality ofrrnB is concluded on the basis of the nonrandom distribution of nucleotide substitutions, the presence of compensating nucleotide covariations, the preservation of secondary and tertiary rRNA structures, and the detection of correctly processed rRNAs in the cell. Comparative sequence analysis also revealed a close evolutionary relationship between rrnB operon of T. chromogena and rrnA operon of another thermophilic actinomycete Thermobispora bispora. We propose thatT. chromogena acquired rrnB operon fromT. bispora or a related organism via horizontal gene transfer.
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Dennis, Patrick P., Sonia Ziesche, and Shanthini Mylvaganam. "Transcription Analysis of Two Disparate rRNA Operons in the Halophilic Archaeon Haloarcula marismortui." Journal of Bacteriology 180, no. 18 (1998): 4804–13. http://dx.doi.org/10.1128/jb.180.18.4804-4813.1998.
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ABSTRACT The genome of the halophilic archaeon Haloarcula marismortui contains two rRNA operons designated rrnAand rrnB. Genomic clones of the two operons and their flanking regions have been sequenced, and primary transcripts and processing intermediates derived from each operon have been characterized. The 16S, 23S, and 5S genes from the two operons were found to differ at 74 of 1,472 positions, 39 of 2,922 positions, and 2 of 122 positions, respectively. This degree of sequence divergence for multicopy (paralogous) rRNA genes was 10- to 50-fold or more higher than anticipated. The two operons exhibit other profound differences that include (i) the presence in rrnA and the absence inrrnB of tRNAAla and tRNACys genes in the intergenic and distal regions, respectively, (ii) divergent 5′ flanking sequences, and (iii) distinct pathways for processing and maturation of 16S rRNA. Processing and maturation of 16S and 23S rRNA from rrnA operon transcripts and of 23S rRNA fromrrnB operon transcripts follow the canonical halophilic pathway, whereas maturation of 16S rRNA from rrnB operon transcripts follows an unusual and different pathway that is apparently devoid of any 5′ processing intermediate.
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Reksoprawiro, Ricky, Gabriella Scarlett, Alexander Joseph Ibnu Wibowo, and Novi Amelia. "Consumer Culture Theory: Hubungan Timbal Balik antar Social Operant Resources dan Operand Resources dalam Studi Empiris McDonald’s Indonesia." Kajian Branding Indonesia 2, no. 1 (2020): 132–61. http://dx.doi.org/10.21632/kbi.2.1.132-161.
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Penelitian ini bertujuan untuk menguji secara empiris secara garis besar untuk mengetahui hubungan antara konsep social operant resources terhadap operand resources yang dilandasi oleh consumer culture theory. Secara spesifik, studi ini ingin menguji sebagai berikut: (i) pengaruh social operant resources terhadap economic operand resources; (ii) pengaruh social operant resources terhadap material operand resources; (iii) pengaruh economic operand resources terhadap social operant resources; dan (iv) pengaruh material operand resources terhadap social operant resources; (v) hubungan timbal balik antara social operant resources dan economic operand resources; (vi) hubungan timbal balik antara social operant resources dan material operand resources. Permasalahan dalam studi ini ditelaah dengan berbasis pada konsep consumer culture theory (CCT). Pengumpulan data primer dilakukan menggunakan kuesioner melalui survei online. Seluruh indikator diukur menggunakan skala Likert tujuh poin. Penelitian ini berhasil memperoleh data responden sebanyak 358 orang konsumen restoran McDonald’s. Teknik analisis faktor eksploratori exploratory factor analysis (EFA) diterapkan untuk melakukan uji validitas konstruk. Selanjutnya, keenam hipotesis diuji menggunakan teknik structural equation modeling (SEM). Hasil studi ini berhasil membuktikan bahwa keenam hipotesis yang diajukan tidak ditolak. Secara ringkas, social operant resources memengaruhi economic operand resources, social operant resources memengaruhi material operand resources, economic operand resources memengaruhi social operant resources, material operand resources memengaruhi social operant resources, ada hubungan timbal balik antara social operant resources dan economic material resources, dan ada hubungan timbal balik antara social operant resources dan material operand resources.
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Menendez, M. C., M. J. Garcia, M. C. Navarro, et al. "Characterization of an rRNA Operon (rrnB) of Mycobacterium fortuitum and Other Mycobacterial Species: Implications for the Classification of Mycobacteria." Journal of Bacteriology 184, no. 4 (2002): 1078–88. http://dx.doi.org/10.1128/jb.184.4.1078-1088.2002.
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ABSTRACT Mycobacteria are thought to have either one or two rRNA operons per genome. All mycobacteria investigated to date have an operon, designated rrnA, located downstream from the murA gene. We report that Mycobacteriun fortuitum has a second rrn operon, designated rrnB, which is located downstream from the tyrS gene; tyrS is very close to the 3" end of a gene (3-mag) coding for 3-methylpurine-DNA-glycosylase. The second rrn operon of Mycobacterium smegmatis was shown to have a similar organization, namely, 5" 3-mag-tyrS-rrnB 3". The rrnB operon of M. fortuitum was found to have a single dedicated promoter. During exponential growth in a rich medium, the rrnB and rrnA operons were the major and minor contributors, respectively, to pre-rRNA synthesis. Genomic DNA was isolated from eight other fast-growing mycobacterial species. Samples were investigated by Southern blot analysis using probes for murA, tyrS, and 16S rRNA sequences. The results revealed that both rrnA and rrnB operons were present in each species. The results form the basis for a proposed new scheme for the classification of mycobacteria. The approach, which is phylogenetic in concept, is based on particular properties of the rrn operons of a cell, namely, the number per genome and a feature of 16S rRNA gene sequences.
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Asai, Tsuneaki, Ciarán Condon, Justina Voulgaris, et al. "Construction and Initial Characterization of Escherichia coli Strains with Few or No Intact Chromosomal rRNA Operons." Journal of Bacteriology 181, no. 12 (1999): 3803–9. http://dx.doi.org/10.1128/jb.181.12.3803-3809.1999.
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ABSTRACT The Escherichia coli genome carries seven rRNA (rrn) operons, each containing three rRNA genes. The presence of multiple operons has been an obstacle to many studies of rRNA because the effect of mutations in one operon is diluted by the six remaining wild-type copies. To create a tool useful for manipulating rRNA, we sequentially inactivated from one to all seven of these operons with deletions spanning the 16S and 23S rRNA genes. In the final strain, carrying no intact rRNA operon on the chromosome, rRNA molecules were expressed from a multicopy plasmid containing a single rRNA operon (prrn). Characterization of these rrndeletion strains revealed that deletion of two operons was required to observe a reduction in the growth rate and rRNA/protein ratio. When the number of deletions was extended from three to six, the decrease in the growth rate was slightly more than the decrease in the rRNA/protein ratio, suggesting that ribosome efficiency was reduced. This reduction was most pronounced in the Δ7 prrn strain, in which the growth rate, unlike the rRNA/protein ratio, was not completely restored to wild-type levels by a cloned rRNA operon. The decreases in growth rate and rRNA/protein ratio were surprisingly moderate in the rrndeletion strains; the presence of even a single operon on the chromosome was able to produce as much as 56% of wild-type levels of rRNA. We discuss possible applications of these strains in rRNA studies.
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Lakhova, Tatiana N., Fedor V. Kazantsev, Aleksey M. Mukhin, Nikolay A. Kolchanov, Yury G. Matushkin, and Sergey A. Lashin. "Algorithm for the Reconstruction of Mathematical Frame Models of Bacterial Transcription Regulation." Mathematics 10, no. 23 (2022): 4480. http://dx.doi.org/10.3390/math10234480.
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Transcription regulation plays an important role in bacterial activity. The operon concept coined by François Jacob and Jacques Monod has had a considerable effect on investigations into gene expression regulation, including modeling. However, most such studies have considered the regulation models devised manually for one or several operons. For that reason, the objective of the present study was automated genome model reconstruction for different bacteria. The suggested algorithm accounted for all possible interactions of transcription factors and their binding sites in an operon’s promoter region. Transcription factor enumeration was performed using the deep-first search technique. The obtained models are of interest for those involved in the research of transcription factor regulatory effects on bacterial gene expression in microbiology and biotechnology.