Programmed Alternative Reading Of The Genetic Code

1. Introduction.- 2. The Translational Machinery.- 3. Errors During Elongation Can Cause Translational Frameshifting.- 4. Programmed +1 Frameshifting.- 5. Programmed?1 Frameshifting in Eukaryotes.- 6. Programmed?1 Frameshift Sites in Prokaryotes.- 7. tRNA Hopping.- 8. Programmed Readthrough of Translational Termination Codons.- 9. Programmed Alternative Decoding as Programmed Translational Errors.- 10. Concluding Remarks.

The explosion of the field of genetics over the last decade, with the new technologies that have stimulated research, suggests that a new sort of reference work is needed to keep pace with such a fast-moving and interdisciplinary field. Brenner's Encyclopedia of Genetics, Second Edition, Seven Volume Set, builds on the foundation of the first edition by addressing many of the key subfields of genetics that were just in their infancy when the first edition was published. The currency and accessibility of this foundational content will be unrivalled, making this work useful for scientists and non-scientists alike. Featuring relatively short entries on genetics topics written by experts in that topic, Brenner's Encyclopedia of Genetics, Second Edition, Seven Volume Set provides an effective way to quickly learn about any aspect of genetics, from Abortive Transduction to Zygotes. Adding to its utility, the work provides short entries that briefly define key terms, and a guide to additional reading and relevant websites for further study. Many of the entries include figures to explain difficult concepts. Key terms in related areas such as biochemistry, cell, and molecular biology are also included, and there are entries that describe historical figures in genetics, providing insights into their careers and discoveries. This 7-volume set represents a 25% expansion from the first edition, with over 1600 articles encompassing this burgeoning field Thoroughly up-to-date, with many new topics and subfields covered that were in their infancy or not inexistence at the time of the first edition. Timely coverage of emergent areas such as epigenetics, personalized genomic medicine, pharmacogenetics, and genetic enhancement technologies Interdisciplinary and global in its outlook, as befits the field of genetics Brief articles, written by experts in the field, which not only discuss, define, and explain key elements of the field, but also provide definition of key terms, suggestions for further reading, and biographical sketches of the key people in the history of genetics

Early Thoughts on RNA and the Origin of Life The full impact of the essential role of the nucleic acids in biological systems was forcefully demonstrated by the research community in the 1950s. Although Avery and his collaborators had identified DNA as the genetic material responsible for the transformation of bacteria in 1944, it was not until the early 1950s that the Hershey-Chase experiments provided a more direct demonstration of this role. Finally, the structural DNA double helix proposed by Watson and Crick in 1953 clearly created a structural frame work for the role of DNA as both information carrier and as a molecule that could undergo the necessary replication needed for daughter cells. Research continued by Kornberg and his colleagues in the mid-1950s emphasized the biochemistry and enzymology of DNA replication. At the same time, there was a growing interest in the role of RNA. The 1956 dis covery by David Davies and myself showed that polyadenylic acid and polyuridylic acid could form a double-helical RNA molecule but that it differed somewhat from DN A A large number of experiments were subsequendy carried out with synthetic polyribonucleotides which illustrated that RNA could form even more complicated helical structures in which the specificity of hydrogen bonding was the key element in determining the molecular conformation. Finally, in I960,1 could show that it was possible to make a hybrid helix.

The literature on recoding is scattered, so this superb book ?lls a need by prov- ing up-to-date, comprehensive, authoritative reviews of the many kinds of recoding phenomena. Between 1961 and 1966 my colleagues and I deciphered the genetic code in Escherichia coli and showed that the genetic code is the same in E. coli, Xenopus laevis, and guinea pig tissues. These results showed that the code has been c- served during evolution and strongly suggested that the code appeared very early during biological evolution, that all forms of life on earth descended from a c- mon ancestor, and thus that all forms of life on this planet are related to one another. The problem of biological time was solved by encoding information in DNA and retrieving the information for each new generation, for it is easier to make a new organism than it is to repair an aging, malfunctioning one. Subsequently, small modi?cations of the standard genetic code were found in certain organisms and in mitochondria. Mitochondrial DNA only encodes about 10–13 proteins, so some modi?cations of the genetic code are tolerated that pr- ably would be lethal if applied to the thousands of kinds of proteins encoded by genomic DNA.

SARS was the ?rst new plague of the twenty-?rst century. Within months, it spread worldwide from its “birthplace” in Guangdong Province, China, affecting over 8,000 people in 25 countries and territories across ?ve continents. SARS exposed the vulnerability of our modern globalised world to the spread of a new emerging infection. SARS (or a similar new emerging disease) could neither have spread so rapidly nor had such a great global impact even 50 years ago, and arguably, it was itself a product of our global inter-connectedness. Increasing af?uence and a demand for wild-game as exotic food led to the development of large trade of live animal and game animal markets where many species of wild and domestic animals were co-housed, providing the ideal opportunities for inter-species tra- mission of viruses and other microbes. Once such a virus jumped species and attacked humans, the increased human mobility allowed the virus the opportunity for rapid spread. An infected patient from Guangdong who stayed for one day at a hotel in Hong Kong led to the transmission of the disease to 16 other guests who travelled on to seed outbreaks of the disease in Toronto, Singapore, and Vietnam, as well as within Hong Kong itself. The virus exploited the practices used in modern intensive care of patients with severe respiratory disease and the weakness in infection control practices within our health care systems to cause outbreaks within hospitals, further amplifying the spread of the disease. Health-care itself has become a two-edged sword.

Transfer RNA in Protein Synthesis is a comprehensive volume focusing on important aspects of codon usage, selection, and discrimination in the genetic code. The many different functions of tRNA and the specialized roles of the corresponding codewords in protein synthesis from initiation through termination are thoroughly discussed. Variations that occur in the initiation process, in reading the genetic code, and in the selection of codons are discussed in detail. The book also examines the role of modified nucleosides in tRNA interactions, tRNA discrimination in aminoacylation, codon discrimination in translation, and selective use of termination codons. Other topics covered include the adaptation of the tRNA population to codon usage in cells and cellular organelles, the occurence of UGA as a codon for selenocysteine in the universal genetic code, new insights into translational context effects and in codon bias, and the molecular biology of tRNA in retroviruses. The contributions of outstanding molecular biologists engaged in tRNA research and prominent investigators from other scientific disciplines, specifically retroviral research, make Transfer RNA in Protein Synthesis an essential reference work for microbiologists, biochemists, molecular biologists, geneticists, and other researchers involved in protein synthesis research.

The fission yeast Schizosaccharomyces pombe is the favoured tool of many productive research groups throughout the world, serving as a useful model for fundamental principles and mechanisms, such as genome organization, differential gene regulation, cell-cycle control, signal transduction, or cellular morphogenesis. This book collates the current state of knowledge derived from molecular studies in this simple eukaryotic microorganism. The entire sequence of its genome has been completed, emphasizing the comparative value and model status of this yeast. The individual chapters, highlighting up-to-date views on prominent aspects of molecular organization, were written by active research scientists, presenting the results of their investigations to other workers in neighbouring fields. This book intends to serve the fission yeast community as a handy source of reference for years to come. It will also be of particular value to the ever-increasing number of researchers starting to look into fission yeast affairs for comparative reasons from other platforms of molecular genetics and cell biology.