Download or read book Helicase and DNA Replication Activities of SV40 Large T Antigen written by Kyungok Wun-Kim and published by . This book was released on 1992 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book SV40 Large T Antigen Helicase written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: To initiate DNA replication, SV40 large T antigen needs to recognize and bind to the origin in SV40 DNA. This is achieved through sequence specific contacts between the T antigen origin binding domain (OBD) and the pentanucleotide regions in the center of the origin, as well as non-sequence specific interactions between the helicase domain and the EP and AT regions of the origin. This leads to the assembly of a double hexamer of T antigen over a melted origin DNA. Subsequently, the DNA becomes unwound bidirectionally, providing SS DNA templates for DNA replication. However, these events are not fully understood. For instance, it is not clear how T antigen separates DS DNA at the origin or how the separated strands become threaded through the double hexamer. In this dissertation, I identified a new unwinding activity of large T antigen. The helicase can unwind the central pentanucleotides in an ATP-hydrolysis dependent way. This activity of T antigen, like its structural distortion activity that acts on the flanking EP and AT regions, is an indispensable component of the unwinding of the entire origin. Specific sequences in the pentanucleotide region are necessary for the activity, and the flanking AT track can stimulate it. The SV40 hexameric helicase consists of a positively charged central channel and six hydrophilic channels in the large tiers. The hydrophilic channels separate adjacent large tier domains within each hexamer. In this dissertation, I generated a series of mutants with single-point substitutions in the hydrophilic channels and studied the function of the hydrophilic channels in SV40 DNA replication. The mutants were characterized in various biochemical assays and grouped into four major classes according to their properties. One class of mutant proteins (class A-D429A, N449S and N515S) displayed normal DNA binding, ATPase, and helicase activities. However, they were defective specifically at unwinding origin DNA. The three mutants were found to be deficient in EP melting activity. Two of them (D429A and N515S) also failed to unwind the central pentanucleotide region of the origin. Taken together, my data indicate that the hydrophilic channels play active roles in unwinding the origin to provide the single-stranded substrates for DNA replication. Based on my results and on published structural and functional information, a model is proposed in this dissertation to illustrate how T antigen could separate the pentanucleotide region at the center of the origin. My data also suggest a mechanism by which the step-wise assembly of the T antigen double hexamer could trigger unwinding of the origin.
Download or read book Monitoring SV40 Large T Antigen Helicase Activity Using Surface Plasmon Resonance written by Jason Robert Plyler and published by . This book was released on 2009 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Viruses and Human Disease written by Ellen G. Strauss and published by Elsevier. This book was released on 2007-09-21 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: Completely revised and updated, the new edition of this groundbreaking text integrates basic virology with pathophysiological conditions to examine the connection between virology and human disease. Most virology textbooks focus on the molecular biology involved without adequate reference to physiology. This text focuses on viruses that infect humans, domestic animals and vertebrates and is based on extensive course notes from James Strauss' virology class at the California Institute of Technology taught for over 30 years. Expertly depicting in color the molecular structure and replication of each virus, it provides an excellent overview for students and professionals interested in viruses as agents of human disease. - Includes over 30% new material - virtually all of the figures and tables have been redrawn to include the latest information and the text has been extensively rewritten to include the most up-to-date information - Includes a new chapter on emerging and reemerging viral diseases such as avian flu, SARS, the spread of West Nile virus across America, and the continuing spread of Nipah virus in Southeast Asia - Further reading sections at the end of each chapter make it easy find key references - World maps depicting the current distribution of existing and newly emerging viruses are also incorporated into the text
Download or read book DNA Tumor Viruses written by Blossom Damania and published by Springer Science & Business Media. This book was released on 2008-12-19 with total page 805 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique book focuses on the DNA viruses in the human population that are associated with cancers. It covers most of the viruses that are thought to contribute to human malignancy. This book represents a comprehensive review of the field of DNA tumor virology. Right now, while there are books out there that cover individual viruses that are also covered in this book, there is no single book that covers this topic comprehensively. This book is the first current, comprehensive review of its kind in the market.
Download or read book GENETIC AND BIOCHEMICAL ANALYSIS OF SV40 LARGE T ANTIGEN HOST INTERACTIONS T ANTIGEN written by DAVID CHARLES KOHRMAN and published by . This book was released on 1991 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: p185 may be functionally important.
Download or read book Molecular Mechanism of SV40 Large Tumor Antigen Helicase written by Etienne Tokonzaba and published by . This book was released on 2007 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cellular Proteins Associated with SV40 Small T Antigen written by Yu-Chung Yang and published by . This book was released on 1981 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Properties of SV40 Large T Antigen Involved in the Replication of SV40 DNA written by Ian Jeffrey Mohr and published by . This book was released on 1989 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mutational Analysis of the Central Channel in the Simian Virus 40 Large T Antigen Helicase written by David Manna and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: I report in this dissertation that residues lining the small tier of the central channel have an important role in DNA binding, especially in single-stranded DNA binding. Defects in helicase activity for the small tier channel mutants can be accounted by their corresponding defects in DNA binding. One of the large tier central channel mutants (R456A) showed a defect in unwinding of origin DNA, but this could not be attributed to a problem in DNA binding. Combined with the results of others, it appears that the large tier is primarily involved in unwinding origin DNA. These findings are incorporated into a model of T antigen helicase activity where single-stranded DNA is looped out of one hexamer through hydrophilic side-channels in the large tier of the hexamer. The looped-out single-stranded DNA runs back into the origin binding domain of the adjacent hexamer. In this model, there is one strand of DNA within each small tier during DNA unwinding from the origin. (Abstract shortened by UMI.).
Download or read book Initiation of Simian Virus 40 SV40 DNA Replication written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: It is well established that during initiation of SV40 DNA synthesis, a double hexamer of T antigen forms over the origin and acts as a bidirectional helicase. The subsequent events are much less clear. In fact, the structure on which DNA synthesis begins is not known, but has been hypothesized to be the double hexamer tightly associated with cellular initiation factors replication protein A (RPA), topoisomerase I (topo I) and more loosely with DNA polymerase & alpha;/primase (pol/prim). I now demonstrate that after a double hexamer forms over small origin fragments, a new structure consisting of a single hexamer associated with DNA is generated in an ATP dependent reaction from double hexamers. This structure, called the preinitiation complex (PIC), requires about 5 minutes to form whereas double hexamers are generated within 20 seconds. Importantly, PICs can associate with RPA and topo I whereas double hexamers, which have not been converted to PICs, can only bind to topo I. PICs are not simply T antigen hexamers associated with single-stranded DNA as the latter structures were shown not to bind RPA or topo I. Topo I can bind to an RPA-associated PIC, but RPA cannot bind to a topo I-associated PIC suggesting that the binding order is RPA then topo I. Importantly, DNA synthesis activity appears to be associated with the PICs but not with double hexamers. In this dissertation, a series of mutants with single-point substitutions in the helicase domain are generated to discover activities required for initiation of DNA replication. Four of these mutants (456 RA, 460ED, 462GA, and 499DA) are normal in their ability to hydrolyze ATP and are capable of associating into double hexamers in the presence of origin DNA. Furthermore, they possess normal ability to bind to single-stranded DNA. However, they fail to melt the early palindrome region of the origin. They also are severely impaired in unwinding origin-containing DNA fragments and in carrying out a helicase reaction with an M13 partial duplex DNA substrate. Interestingly, these mutants retain some ability to perform a helicase reaction with artificial replication forks, indicating that their intrinsic helicase activity is functional. Intriguingly, these mutants have almost completely lost their ability to bind to double-stranded DNA nonspecifically. Taken together, my data indicate that structural distortion and subsequent unwinding of the origin depend upon T antigen's ability to bind to DNA nonspecifically.
Download or read book A mutational analysis of the SV40 small T antigen written by Pratima Jog and published by . This book was released on 1990 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Stem Cells written by Anthony Atala and published by Academic Press. This book was released on 2012-12-31 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt: New discoveries in the field of stem cells increasingly dominate the news and scientific literature revealing an avalanche of new knowledge and research tools that are producing therapies for cancer, heart disease, diabetes, and a wide variety of other diseases that afflict humanity. The Handbook of Stem Cells integrates this exciting area of life science, combining in two volumes the requisites for a general understanding of adult and embryonic stem cells. Organized in two volumes entitled Pluripotent Stem Cells and Cell Biology and Adult and Fetal Stem Cells, this work contains contributions from the world's experts in stem cell research to provide a description of the tools, methods, and experimental protocols needed to study and characterize stem cells and progenitor populations as well as a the latest information of what is known about each specific organ system. - Provides comprehensive coverage on this highly topical subject - Contains contributions by the foremost authorities and premiere names in the field of stem cell research - Companion website - http://booksite.elsevier.com/9780123859426/ - contains over 250 color figures in presentation format
Download or read book Small DNA Tumour Viruses written by Kevin Gaston and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this timely book leading scientists from around the world review current hot-topics in this area providing a fascinating overview of the molecular biology of these viruses and their interactions with the host. Topics covered include: HPV infections and the production of HPV virion stocks; viral oncoproteins and their functions; the replication and maintenance of viral genomes; virus induced alterations in cellular miRNAs; viral deregulation of DNA damage responses; the initiation of viral DNA replication; induction of genomic instability by viral oncoproteins; targeting of PML proteins and.
Download or read book Systems Biology of Cancer written by Sam Thiagalingam and published by Cambridge University Press. This book was released on 2015-04-09 with total page 597 pages. Available in PDF, EPUB and Kindle. Book excerpt: An overview of the current systems biology-based knowledge and the experimental approaches for deciphering the biological basis of cancer.
Download or read book Chromosome Biology written by Rudi Appels and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chromosome biology has been brought to a golden age by phenomenal advanced in molecular genetics and techniques. This is true in the plant arena, and it is becoming increasingly true in animal studies, where chromosomes are more difficult to work with. With advanced knowledge of transformation, scientists can tell exactly where a new element enters a chromosome. Conversely, molecular biologists can make large mistakes if they do not understand the behavior of chromosomes. Written by internationally recognized experts in the field, this book is the most authoritative work on the subject to date. Students of genetics, crop science and plant breeding, entomology, animal science, and related fields will benefit from this comprehensive and practical textbook.
Download or read book Oral Head and Neck Oncology and Reconstructive Surgery E Book written by R. Bryan Bell and published by Elsevier Health Sciences. This book was released on 2017-08-25 with total page 967 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oral, Head and Neck Oncology and Reconstructive Surgery is the first multidisciplinary text to provide readers with a system for managing adult head and neck cancers based upon stage. Using an evidence-based approach to the management and treatment of a wide variety of clinical conditions, the extensive experience of the author and contributors in head and neck surgery and oncology are highlighted throughout the text. This includes computer aided surgical simulation, intraoperative navigation, robotic surgery, endoscopic surgery, microvascular reconstructive surgery, molecular science, and tumor immunology. In addition, high quality photos and illustrations are included, which are easily accessible on mobile devices. - Management protocols and outcomes assessment provide clear guidelines for managing problems related to adult head and neck oncology and reconstructive surgery. - State-of-the art guidance by recognized experts details current techniques as well as technological advances in head and neck/cranio-maxillofacial surgery and oncology. - Evidence-based content details the latest diagnostic and therapeutic options for treating a wide-variety of clinical problems with an emphasis on surgical technique and outcomes. - Multidisciplinary approach reflects best practices in managing head and neck oncology and cranio-maxillofacial surgery. - 900 highly detailed images clearly demonstrate pathologies and procedures. - Designed for the modern classroom which lets you access important information anywhere through mobile tablets and smart phones.
