Download or read book Regulation of the Escherichia Coli Nrd Operons by NrdR written by Sowmya Somashekar Reddy and published by . This book was released on 2010 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ribonucleotide reductase (RNR) is the critical enzyme in most organisms that catalyses the synthesis of deoxyribonucleotides (dNTPs). In E. coli there are three RNR operons: nrdAB , nrdHIEF and nrdDG . NrdR is a conserved transcriptional repressor of the operons encoding RNR in many organisms. Previously it has been shown that the nrdHIEF operon of E. coli is induced under oxidative and nitrosative stress conditions, but the molecular mechanism of this induction is not known. The study describes the link between NrdR and low dNTP levels and the possible regulatory mechanisms of the nrdHIEF operon. Evidence is presented to suggest that NrdR may be a sensor of low dNTPs levels. A striking result obtained is that the nrdHIEF operon may also be regulated by a small RNA whose origin still remains unknown. Lastly, it is shown that the spacing between the NrdR boxes in nrdHIEF promoter is important and may be involved in a formation of a loop to achieve repression.
Download or read book Characterization of the Escherichia Coli Transcriptional Regulator NrdR written by Brandon Lee McKethan and published by . This book was released on 2013 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ribonucleotide reductases (RNRs) are ancient enzymes that provide the only known pathway for the production of deoxyribonucleotides, and as such are vital to all living organisms for the synthesis and repair of DNA. In Escherichia coli , three RNR isoenzymes are encoded by three distinct nrd operons, the expression of which is regulated by an array of transcriptional activators and repressors. One such regulator, NrdR, was recently identified and shown to repress all three operons in E. coli . NrdR contains an ATP-cone domain that is homologous to the allosteric activity site of certain RNRs, and NrdR is thought to have arisen from the duplication and genomic rearrangement of an nrd gene. It has been hypothesized that repression of nrd operons by NrdR is regulated by nucleotide binding, with dATP stimulating repression and ATP alleviating it. However, direct biochemical evidence for this model has not been established. We utilized an NrdR apoprotein to test the discrete effects of various adenosine nucleotides on NrdR function. We demonstrated that the binding of nucleotides to NrdR is regulated by a negatively cooperative mechanism, and that neither ATP nor dATP can fully occupy the protein. We further found that this allosteric interaction requires the formation of homo-oligomeric complexes of NrdR. We determined that NrdR binds a variety of adenosine nucleotides in vivo , including tri-, di- and monophoshates. Our findings indicate that NrdR biochemistry is primarily regulated by the length of the bound nucleotide's phosphate chain. In contrast with previous hypotheses, our data show that both ATP and dATP abolish the ability of NrdR to bind DNA, while AMP and dAMP induce specific binding of NrdR to its cognate promoter. Our findings suggest that NrdR directly binds ATP and dATP in vivo and that this form is incapable of binding DNA. These bound nucleotides are then hydrolyzed in situ to their monophosphate counterparts by an unknown process. The resultant AMP/dAMP bound NrdR has increased DNA binding affinity and can repress nrd operons. This model, while still speculative, represents a significantly more complex mechanism of regulation than has been previously theorized.
Download or read book Regulation of E Coli Nrd Operon Encoding Ribonucleotide Reductase written by Lei Sun and published by . This book was released on 1993 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ribonucleotide Reductase written by Kristoffer Andersson and published by Nova Publishers. This book was released on 2008 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of this book is the amazing enzyme ribonucleotide reductase (RNR), the enzyme responsible for the conversion of ribonucleotides to deoxyribonucleotides. The prerequisite for DNA-synthesis and DNA-repair in all living cells is the supply of the four deoxyribonucleotides. Such molecules result from the enzymatically difficult radical-induced reduction of ribonucleotides, a multistep chemical process catalyzed by RNR. RNR was the first enzyme in which the presence of an amino acid radical (a tyrosyl) in E. coli Class Ia RNR has been proven; since then several other biological amino acid radical species have been found on e.g. tryptophan, glycine, cysteine, lysine residues and on amino acid derived small cofactors like 2 tryptophanes in thryptophan-trypthanyl-radical or cysteine-tyrosyl-radical in other enzymes. As all known cellular life forms store their genetic information as DNA, RNR is likely to be found in all growing cells of every living organism, a fact that is confirmed by a rapidly increasing number of genomic screenings.
Download or read book Genetic Control of Malaria and Dengue written by Zach N. Adelman and published by Academic Press. This book was released on 2015-10-15 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: Genetic Control of Malaria and Dengue focuses on the knowledge, technology, regulation and ethics of using genetically modified mosquitoes to interrupt the transmission of important vector-borne diseases including Malaria. It contains coverage of the current state of knowledge of vector-borne diseases and how they are currently controlled; vaccine, drug and insecticide development; various strategies for altering the genome of mosquitoes in beneficial ways; and the regulatory, ethical and social environment concerning these strategies. For more than five decades, the prospect of using genetically-modified mosquitoes to control vector-borne disease transmission has been a purely hypothetical scenario. We simply did not have the technology or basic knowledge to be able to do it. With the explosion of field trials and potential interventions in development, Genetic Control of Malaria and Dengue provides a comprehensive overview of research in genetics, microbiology, virology, and ecology involved in the development and implementation of genetic modification programs for virus and disease control. This book is meant to provide a practical guide to researchers, regulators and the general public about how this technology actually works, how it can be improved, and what is still unknown. - Includes coverage of vectorial capacity, critical to understanding vector-borne disease transmission - Provides a summary of the concepts of both population suppression and population replacement - Contains pivotal coverage of ethical and ecological ramifications of genetics-based control strategies
Download or read book The Trypanosomiases written by Ian Maudlin and published by CABI. This book was released on 2004-07-09 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt: This state-of-the-art reference book includes comprehensive coverage of the biology and control of African, Asian and South American trypanosomiasis ("sleeping sickness") in man and animals. It describes recent research developments in the biology and molecular biology of trypanosomes (the protozoan parasite) and their vectors, and methods in diagnosis and control, such as trapping tsetse fly vectors. Different sections of the book are devoted to biology of trypanosomes, vector biology, epidemiology and diagnosis, pathogenesis, disease impact, chemotherapy and disease control, and vector control. The book contains contributions from leading experts from Europe, North and South America, and Africa.
Download or read book The Resolution Revolution Recent Advances In cryoEM written by and published by Academic Press. This book was released on 2016-08-26 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: cryoEM, a new volume in the Methods in Enzymology series, continues the legacy of this premier serial with quality chapters authored by leaders in the field. This volume covers research methods and new developments in recording images, the creation, evaluation and validation of 3D maps from the images, model building into maps and refinement of the resulting atomic structures, and applications of essentially single particle methods to helical structures and to sub-tomogram averaging. - Continues the legacy of this premier serial with quality chapters authored by leaders in the field - Covers research methods that determine the structures of biological molecules, a vital step for understanding their function - Contains the technical developments underpinning the advances of cryoEM and captures the exciting insights that have resulted
Download or read book Cancer Proteomics written by Sayed S. Daoud and published by Springer Science & Business Media. This book was released on 2008 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers current topics related to the use of proteomic strategies in cancer therapy as well as anticipated challenges that may arise from its application in daily practice. It details current technologies used in proteomics, examines the use proteomics in cell signaling, presents clinical applications of proteomics in cancer therapy, and looks at the role of the FDA in regulating the use of proteomics.
Download or read book Antimicrobial Therapies written by Carlos Barreiro (Editor) and published by . This book was released on 2021 with total page 443 pages. Available in PDF, EPUB and Kindle. Book excerpt: Antimicrobial resistance will become a global health threat since antimicrobial treatments continue at the forefront of the defense against microbial infections. To respond to the issue, this detailed book explores vital methodologies currently in use to advance our understanding of antibiotic issues and answer the worldwide demand for novel antibiotics therapies. Beginning with a review chapter that guides the reader through the worldwide demand for novel antibiotics therapies, the volume continues with sections covering new screening procedures and environmental sources, advances in analytical, microbiological, and biotechnological methodologies, antibiotic production and antibiotic resistances, as well as considerations of drug trials and clinical concerns regarding multi-resistant patients. Written for the highly successful Methods in Molecular Biology series, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and practical, Antimicrobial Therapies: Methods and Protocols provides a reference source for health, laboratory, and industrial professionals, as well as for graduate students in a number of bio-sanitary disciplines, including medicine, nursery, biotechnology, veterinary, microbiology, genetics, molecular biology, nutrition, farming, and more.
Download or read book Clinical Mycology written by William E. Dismukes and published by . This book was released on 2003 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: Within the field of infectious diseases, medical mycology has experienced significant growth over the last decade. Invasive fungal infections have been increasing in many patient populations, including: those with AIDS; transplant recipients; and the elderly. As these populations grow, so does the diversity of fungal pathogens. Paralleling this development, there have been recent launches of several new antifungal drugs and therapies. Clinical Mycology offers a comprehensive review of this discipline. Organized by types of fungi, this volume covers microbiologic, epidemiologic and demographic aspects of fungal infections as well as diagnostic, clinical, therapeutic, and preventive approaches. Special patient populations are also detailed.
Download or read book Epigenetic Shaping of Sociosexual Interactions From Plants to Humans written by and published by Academic Press. This book was released on 2014-08-22 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: Epigenetic Shaping of Sociosexual Interactions: From Plants to Humans is the first attempt to interpret the higher social functions of organisms. This volume covers an extraordinarily wide range of biological research and provides a novel framework for understanding human-specific brain functions. Covers an extraordinarily wide range of biological research Provides a novel framework for understanding human-specific brain functions.
Download or read book XIII Mediterranean Conference on Medical and Biological Engineering and Computing 2013 written by Laura M. Roa Romero and published by Springer Science & Business Media. This book was released on 2013-10-01 with total page 1978 pages. Available in PDF, EPUB and Kindle. Book excerpt: The general theme of MEDICON 2013 is "Research and Development of Technology for Sustainable Healthcare". This decade is being characterized by the appearance and use of emergent technologies under development. This situation has produced a tremendous impact on Medicine and Biology from which it is expected an unparalleled evolution in these disciplines towards novel concept and practices. The consequence will be a significant improvement in health care and well-fare, i.e. the shift from a reactive medicine to a preventive medicine. This shift implies that the citizen will play an important role in the healthcare delivery process, what requires a comprehensive and personalized assistance. In this context, society will meet emerging media, incorporated to all objects, capable of providing a seamless, adaptive, anticipatory, unobtrusive and pervasive assistance. The challenge will be to remove current barriers related to the lack of knowledge required to produce new opportunities for all the society, while new paradigms are created for this inclusive society to be socially and economically sustainable, and respectful with the environment. In this way, these proceedings focus on the convergence of biomedical engineering topics ranging from formalized theory through experimental science and technological development to practical clinical applications.
Download or read book Applied Plant Virology written by L. P. Awasthi and published by Academic Press. This book was released on 2020-05-14 with total page 851 pages. Available in PDF, EPUB and Kindle. Book excerpt: Applied Plant Virology: Advances, Detection, and Antiviral Strategies provides an overview on recent developments and applications in the field of plant virology. The book begins with an introduction to important advances in plant virology, but then covers topics including techniques for assay detection and the diagnosis of plant viruses, the purification, isolation and characterization of plant viruses, the architecture of plant viruses, the replication of plant viruses, the physiology of virus-infected hosts, vectors of plant viruses, and the nomenclature and classification of plants. The book also discusses defense strategies by utilizing antiviral agents and management strategies of virus and viroid diseases. With contributions from an international collection of experts, this book presents a practical resource for plant virologists, plant pathologists, horticulturalists, agronomists, biotechnologists, academics and researchers interested in up-to-date technologies and information that advance the field of plant virology. - Covers the detection, control and management of plant viruses - Discusses antiviral strategies, along with mechanisms of systemic induced resistance to enhance the defense of plants against viruses - Provides contributory chapters from expert plant virologists from different parts of the world
Download or read book Rice Research for Quality Improvement Genomics and Genetic Engineering written by Aryadeep Roychoudhury and published by Springer Nature. This book was released on 2020-10-31 with total page 777 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the conventional breeding approach, and on the latest high-throughput genomics tools and genetic engineering / biotechnological interventions used to improve rice quality. It is the first book to exclusively focus on rice as a major food crop and the application of genomics and genetic engineering approaches to achieve enhanced rice quality in terms of tolerance to various abiotic stresses, resistance to biotic stresses, herbicide resistance, nutritional value, photosynthetic performance, nitrogen use efficiency, and grain yield. The range of topics is quite broad and exhaustive, making the book an essential reference guide for researchers and scientists around the globe who are working in the field of rice genomics and biotechnology. In addition, it provides a road map for rice quality improvement that plant breeders and agriculturists can actively consult to achieve better crop production.
Download or read book Volume Microscopy written by Irene Wacker and published by Humana. This book was released on 2021-07-14 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume discusses different approaches to workflows for large volume electron microscopy - from preparation of samples to their imaging in a variety of microscopes - in some cases also applying correlative techniques. The chapters in this book cover topics such as correlative super resolution and electron microscopy to detect molecules in their native cellular context; low-threshold access to serial section arrays; improving serial blockface SEM by focal charge compensation; FIBSEM analysis of interfaces between hard technical devices and soft neuronal tissue; and image processing for volume electron microscopy. In Neuromethods series style, chapters include the kind of detail and key advice from the specialists needed to get successful results in your laboratory. Cutting-edge and authoritative, Volume Microscopy: Multiscale Imaging with Photons, Electrons, and Ions is a valuable resource for novice and expert scientists interested in learning more about this evolving field.
