Download or read book Studies on the Role of DNA Gyrase and DNA Supercoiling in Escherichia Coli Growth written by Todd Robert Steck and published by . This book was released on 1985 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book In Vivo Study of the Efficiency of Transcription induced DNA Supercoiling in Escherichia Coli written by Dzwokai Ma and published by . This book was released on 1993 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Isolation and Characterization of Escherichia Coli DNA Gyrase Mutations which Inhibit the Growth of Bacteriophage Mu written by Scott H. Shore and published by . This book was released on 1986 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of DNA Supercoiling in Vitro and in Vivo written by David Nelson Cook and published by . This book was released on 1990 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Regulation of Gene Expression in Escherichia coli written by E. C. C. Lin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 1010 pages. Available in PDF, EPUB and Kindle. Book excerpt: This up-to-date guide focuses on the understanding of key regulatory mechanisms governing gene expression in Escherichia coli. Studies of E. coli not only provide the first models of gene regulation, but research continues to yield different control mechanisms.
Download or read book The Impact of Transcription and Nucleoid associated Proteins on DNA Supercoiling in Escherichia Coli and Salmonella Typhimurium written by Andrews Akwasi Agbleke and published by . This book was released on 2013 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bacterial chromosomes are maintained under constant negative supercoiled stress that influences almost all cellular processes including DNA replication, transcription, segregation, site-specific and homologous recombination, and other DNA transposition. The average supercoiling density of the chromosome is generated by gyrase, and supercoil equilibrium is maintained by two other topoisomerases topo I and topo IV. The supercoils generated by gyrase can diffuse over 10 kb domains. The other half of the chromosome's supercoil structure is connected to abundant nucleoid-associated proteins (NAPs). My goal was to characterize factors other than gyrase that participate in generating or regulating supercoil dynamics in Escherichia coli and Salmonella Typhimurium. We discovered that transcription and gyrase catalytic speeds are matched and the two processes are mechanistically linked. Mutation in gyrase with a slow catalytic cycle decreased both diffusible supercoiling and transcription elongation rates. Mutation in RNAP [beta]ʹ-subunit slowed transcription rates, which resulted in increased levels of diffusible supercoiling. To study the effect of NAPs on diffusible supercoiling, y[delta] resolution efficiency in WT, hupA, hupB, and hupAhupB double mutants were measured. The resolution efficiency (diffusible supercoiling density) was maintained better in cells that make HupA homodimers than HupB homodimers. Resolution efficiency dropped 7-fold in strains carrying deletions of both hupA and hupB. Surprisingly, inhibition of transcription did not increase resolution efficiency as it does in WT and single mutants. I propose a new model in which histone-like protein (HU) enhances dynamic chromosome slithering and branching. When HU is absent, the chromosome collapses into a liquid-crystalline form that is good for long term DNA stability but is inhibitory for site-specific recombination and DNA transcription, resulting in decreased growth rate. Finally, I have made E. coli strains with the supercoil sensor inserted at 9 positions in its genome. Resolution data suggest E. coli generates a chromosome with 15% higher diffusible supercoil levels than Salmonella. Perhaps because of this supercoil difference, deletions in FIS are much more severe in Salmonella than in E. coli, which indicates that the supercoil difference causes a different essential gene landscape in these two closely related bacterial species.
Download or read book DNA Topology written by Andrew D. Bates and published by Oxford University Press, USA. This book was released on 2005 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A key aspect of DNA is its ability to form a variety of structures, this book explains the origins and importance of such structures"--Provided by publisher.
Download or read book Studies of DNA Gyrase Activity in Escherichia Coli and Salmonella Enterica Serovar Typhimurium written by Nikolay Rovinskiy and published by . This book was released on 2013 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gyrase introduces negative supercoils into bacterial DNA. In balance with topoisomerase I, it contributes to the maintenance of constant negative DNA supercoiling. It was shown that in Escherichia coli negative supercoil density of pBR322 plasmid is higher than in Salmonella typhimurium. One of the possible explanations of this phenomenon is a difference of DNA gyrase activity between E. coli and S. typhimurium. We developed in vitro assay of gyrase activity which has shown that DNA gyrases of E. coli and S. typhimurium have the same supercoiling end point, but E. coli gyrase works slightly faster than the S. typhimurium enzyme. To see how this rate difference influences supercoiling on the chromosome, the in vivo assay based on excision of sequence surrounded by resolvase sites has been used in various strains. The efficiency of resolvase action correlates with supercoiling density at the resolvase sites. This assay has shown that E. coli gyrB does not significantly influence supercoiling density, but E. coli gyrA relaxes the S. typhimurium chromosome. This fact can be explained by inefficient interaction of E. coli GyrA with S. typhimurium DNA.
Download or read book Mechanistic Studies on DNA Gyrase from Escherichia Coli written by David Paul Weiner and published by . This book was released on 1992 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Antimicrobial Resistance written by Donald L. Jungkind and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: Development and Implications of Antimicrobial Resistance One of the most ominous trends in the field of antimicrobial chemotherapy over the past decade has been the increasing pace of development of antimicrobial resistance among microbial pathogens. The hypothesis that man can discover a magic bullet to always cure a particular infection has proved false. Physicians are now seeing and treating patients for which there are few therapeutic alternatives, and in some cases, none at all. Until recently there was little concern that physicians might be losing the war in our ability to compete with the evolving resistance patterns of microbial pathogens. Now the general public is very aware of the threat to them if they become infected, thanks to cover story articles in major magazines such as Time, Newsweek, newspapers, and other news sources. Antimicrobial resistance is not a novel problem. Shortly after the widespread introduction of penicillin in the early 1940s, the first strains of penicillin-resistant staphylococci were described. Today it is an uncommon event for a clinical laboratory to isolate an S. aureus that is sensitive to penicillin. Other gram-positive strains of bacteria have become resistant, including the exquisitely sensitive Streptococcus pneumoniae. Sensitivity to vancomycin was once so uniform that it was used in routine clinical laboratories as a surrogate marker for whether an organism should be classified as a gram-positive. That criterion can no longer be relied upon because of emerging resistance among some species. Gram-negative bacteria, viruses, fungi, and parasites all have succeeded in developing resistance.
Download or read book Mathematics of DNA Structure Function and Interactions written by Craig John Benham and published by Springer Science & Business Media. This book was released on 2010-04-29 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: Propelled by the success of the sequencing of the human and many related genomes, molecular and cellular biology has delivered significant scientific breakthroughs. Mathematics (broadly defined) continues to play a major role in this effort, helping to discover the secrets of life by working collaboratively with bench biologists, chemists and physicists. Because of its outstanding record of interdisciplinary research and training, the IMA was an ideal venue for the 2007-2008 IMA thematic year on Mathematics of Molecular and Cellular Biology. The kickoff event for this thematic year was a tutorial on Mathematics of Nucleic Acids, followed by the workshop Mathematics of Molecular and Cellular Biology, held September 15--21 at the IMA. This volume is dedicated to the memory of Nicholas R. Cozzarelli, a dynamic leader who fostered research and training at the interface between mathematics and molecular biology. It contains a personal remembrance of Nick Cozzarelli, plus 15 papers contributed by workshop speakers. The papers give an overview of state-of-the-art mathematical approaches to the understanding of DNA structure and function, and the interaction of DNA with proteins that mediate vital life processes.
Download or read book Studies in Supercolling and DNA Gyrase in Escherichia Coli written by Robert James Franco and published by . This book was released on 1987 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book E Coli Growth Transitions and DNA Supercoiling written by Virginia Louise Balke and published by . This book was released on 1988 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Studies on the Role of Type IA DNA Topoisomerases in DNA Metabolism and Genome Maintenance in Escherichia Coli written by Valentine Usongo and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book DNA Structure and Function written by Richard R. Sinden and published by Elsevier. This book was released on 2012-12-02 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: DNA Structure and Function, a timely and comprehensive resource, is intended for any student or scientist interested in DNA structure and its biological implications. The book provides a simple yet comprehensive introduction to nearly all aspects of DNA structure. It also explains current ideas on the biological significance of classic and alternative DNA conformations. Suitable for graduate courses on DNA structure and nucleic acids, the text is also excellent supplemental reading for courses in general biochemistry, molecular biology, and genetics. - Explains basic DNA Structure and function clearly and simply - Contains up-to-date coverage of cruciforms, Z-DNA, triplex DNA, and other DNA conformations - Discusses DNA-protein interactions, chromosomal organization, and biological implications of structure - Highlights key experiments and ideas within boxed sections - Illustrated with 150 diagrams and figures that convey structural and experimental concepts
Download or read book DNA Topoisomerase Protocols written by Mary-Ann Bjornsti and published by Springer Science & Business Media. This book was released on 1999-03-23 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: DNA Topoisomerase Protocols, I: DNA Topology and Enzymes brings together an unprecedented collection of cutting-edge experimental protocols for investigating DNA structure, topology, and DNA topoisomerase function. Described by expert experimentalists who have perfected the techniques, these unfailingly reproducible methods utilize new approaches to study changes in DNA topology (linking number, knotting, catenation, and relaxation) and DNA structure (bending), as well as to assess chromosome structure through FLP-mediated recombination and to analyze bacterial nucleoid structure. State-of-the-art protocols also detail the expression and purification of bacterial, viral, and eukaryotic DNA topoisomerases from a variety of sources, including baculovirus, and bacterial, yeast and mammalian expression systems. A companion volume, DNA Topoisomerase Protocols, v. 2: Enzymology and Drugs, provides detailed protocols to study the catalytic activities of DNA topoisomerases, as well as their specific interactions with topoisomerase-targeted antitumor and antibacterial drugs. DNA Topoisomerase Protocols, I: DNA Topology and Enzymes will be of immense value to the many basic scientists and clinicians who want better to understand and to exploit proficiently the wealth of recent discoveries about chromatin structure and its relation to gene expression, about DNA topoisomerases as the targets of antitumor and antibacterial agents, and about DNA repair.
Download or read book Antibiotic Resistant Bacteria written by Marina Pana and published by BoD – Books on Demand. This book was released on 2012-04-04 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: Antibiotic-resistant bacterial strains remain a major global threat, despite the prevention, diagnosis and antibiotherapy, which have improved considerably. In this thematic issue, the scientists present their results of accomplished studies, in order to provide an updated overview of scientific information and also, to exchange views on new strategies for interventions in antibiotic-resistant bacterial strains cases and outbreaks. As a consequence, the recently developed techniques in this field will contribute to a considerable progress in medical research.
