152 research outputs found
The Zur regulon of Corynebacterium glutamicum ATCC 13032
No full textSchröder J, Jochmann N, Rodionov DA, Tauch A. The Zur regulon of Corynebacterium glutamicum ATCC 13032. BMC Genomics. 2010;11(1): 12.Background Zinc is considered as an essential element for all living organisms, but it can be toxic at large concentrations. Bacteria therefore tightly regulate zinc metabolism. The Cg2502 protein of Corynebacterium glutamicum was a candidate to control zinc metabolism in this species, since it was classified as metalloregulator of the zinc uptake regulator (Zur) subgroup of the ferric uptake regulator (Fur) family of DNA-binding transcription regulators. Results The cg2502 (zur) gene was deleted in the chromosome of C. glutamicum ATCC 13032 by an allelic exchange procedure to generate the zur-deficient mutant C. glutamicum JS2502. Whole-genome DNA microarray hybridizations and real-time RT-PCR assays comparing the gene expression in C. glutamicum JS2502 with that of the wild-type strain detected 18 genes with enhanced expression in the zur mutant. The expression data were combined with results from cross-genome comparisons of shared regulatory sites, revealing the presence of candidate Zur-binding sites in the mapped promoter regions of five transcription units encoding components of potential zinc ABC-type transporters (cg0041-cg0042/cg0043; cg2911-cg2912-cg2913), a putative secreted protein (cg0040), a putative oxidoreductase (cg0795), and a putative P-loop GTPase of the COG0523 protein family (cg0794). Enhanced transcript levels of the respective genes in C. glutamicum JS2502 were verified by real-time RT-PCR, and complementation of the mutant with a wild-type zur gene reversed the effect of differential gene expression. The zinc-dependent expression of the putative cg0042 and cg2911 operons was detected in vivo with a gfp reporter system. Moreover, the zinc-dependent binding of purified Zur protein to double-stranded 40-mer oligonucleotides containing candidate Zur-binding sites was demonstrated in vitro by DNA band shift assays. Conclusion Whole-genome expression profiling and DNA band shift assays demonstrated that Zur directly represses in a zinc-dependent manner the expression of nine genes organized in five transcription units. Accordingly, the Zur (Cg2502) protein is the key transcription regulator for genes involved in zinc homeostasis in C. glutamicum
The Code for Solving Aerodynamic Problems Based on Explicit Godunov-Kolgan-Rodionov Scheme
No full textТворчість В. Родіонова: проблемний діапазон художнього світогляду (Creativity V. Rodionov: problem diapazon of the artistic swiss)
No full textУ статті акцентується увага на творчості В. Родіонова. Зроблено акцент на проблематиці творів письменника; визначено, що діяльність В. Родіонова характеризується актуальністю та вагомістю проблематики, висвітлення якої прямолінійне, позбавлене завуальовувань і спрямоване на екзистенційний аналіз фактів щоденного буття в усіх його проявах, що реалізується на двох рівнях: загальнолюдському й національному.
(The article focuses on the work of V. Rodionov. The emphasis is placed on the problems of the writer’s works. It is determined that V. Rodionov’s activity is characterized by urgency and weight of problems, the coverage of which is straightforward, deprived of veils, and aimed at an existential analysis of the facts of everyday life in all its manifestations, which is realized on two levels: universal and national. The problem range of the universal is due to the analysis of the values of human life. Research in this direction is not accidental, since the artist seeks to form a peculiar view that will cover such aspects as: the depreciation of life and human relationships, despair and loss of spirituality, the presence of a disharmonious movement of society, the value of artistic paintings, literary works at the present stage of development, the problem of modern interpretation the concept of «love», the importance of the phenomenon of memory as a way to integrate the experience of the past into the present, and hence the ability to compare and contrast, to create a projection into the future, to avoid the occurrence of problem situations in different chronological limits. Acute social and moral issues, highlighted in the literary work of V. Rodionov, are usually distinguished by the author. At the heart of every single piece of poetic or prose nature always lies one actual problem. Violation of the profound problems provoked the emergence of didacticism, the narrative of the most important, verbal-fi gurative thinking, but to moralise and insist on the expediency of his statements. V. Rodionov does not strive, since he has the sole purpose of conveying the acuteness of the problem, the avoidance of which will contribute to the progress of the individual and society as a whole.
pH-Sensitive linear amphiphilic block copolymers for transport and controlled release of molecular oxygen
No full textSoft materials for catalysis and encapsulation: From micelles to complex macromolecular architectures
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Controllable Catalysis with Nanoparticles: Bimetallic Alloy Systems and Surface Adsorbates
No full textTransition metal nanoparticles are privileged materials in catalysis due to their high specific surface areas and abundance of active catalytic sites. While many of these catalysts are quite useful, we are only beginning to understand the underlying catalytic mechanisms. Opening the “black box” of nanoparticle catalysis is essential to achieve the ultimate goal of catalysis by design. In this Perspective we highlight recent work addressing the topic of controlled catalysis with bimetallic alloy and “designer” adsorbate-stabilized metal nanoparticles.This work was supported by King Abdullah University of Science and Technology (KAUST)
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