Download or read book Structure Function Relationships of ADP Glucose Pyrophosphorylase and Branching Enzyme written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Conversion of the Potato tuber ADP-glucose Pyrophopshorylase Regulatory Subunit into a Catalytic Subunit. ADP-glucose synthesis, a rate-limiting reaction in starch synthesis, is catalyzed by ADP-glucose pyrophosphorylase (ADPGlc PPase). The enzyme in plants is allosterically activated by 3-phosphoglycerate (3PGA) and inhibited by inorganic phosphate [Pi] and is composed of two subunits as a heterotetramer, a2b2. Subunit a is the catalytic subunit and subunit b is designated as the regulatory subunit. The b subunit increases the affinty of the activator for the catalytic subunit. Recent results have shown that the subunits are derived from the same ancestor subunit as the regulatory subunit can be converted to a catalytically subunit via mutation of just two amino acids. Lys44 and Thr54 in the large subunit from potato tuber were converted to the homologous catalytic subunit residues, Arg33 and Lys43. The activity of the large subunit mutants cannot be readily tested with a co-expressed wild-type small (catalytic) subunit because of the intrinsic activity of the latter. We co-expressed the regulatory-subunit mutants with SmallD145N, an inactive S subunit in which the catalytic Asp145 was mutated. The activity of the small (catalytic) subunit was reduced more than three orders of magnitude. Coexpression of the L subunit double mutant LargeK44R/T54K with SmallD145N generated an enzyme with considerable activity, 10% and 18% of the wildtype enzyme, in the ADP-glucose synthetic and pyrophosphorolytic direction, respectively. Replacement of those two residues in the small subunit by the homologous amino acids in the L subunits (mutations R33K and K43T) decreased the activity one and two orders of magnitude. The wild-type enzyme and SmallD145NLargeK44R/T54K had very similar kinetic properties indicating that the substrate site has been conserved. The fact that only two mutations in the L subunit restored enzyme activity is very strong evidence that the large subunit is derived from the catalytic ancestor. Previous results showed that Asp145 in the small subunit of the wild-type is essential for catalysis, whereas the homologous Asp160 in the Large WT subunit is not. However, in this study, mutation D160N or D160E in the LK44R/T54K subunit abolished the activity, which shows the ancestral essential role of this residue and confirms that the catalysis of SmallD145NLarge K44R/T54K occurs in the L(b) subunit. A phylogenetic tree of the ADP-Glc PPases present in photosynthetic eukaryotes also sheds information about the origin of the subunits. The tree showed that plant Small and Large subunits can be divided into two and four distinct groups, respectively. The two main groups of S subunits are from dicot and monocot plants, whereas Large subunit groups correlate better with their documented tissue expression. The first Large-subunit group is generally expressed in photosynthetic tissues and comprises Large subunits from dicots and monocots. Group II displays a broader expression pattern, whereas groups III and IV are expressed in storage organs (roots, stems, tubers, seeds). Subunits from group III are only from dicot plants, whereas group IV are seed-specific subunits from monocots. These last two groups stem from the same branch of the phylogenetic tree and split before monocot and dicot separation. Thus few as two mutations turned the L subunit from Solanum tuberosum catalytic, showing that L and S subunits share a common catalytic ancestor, rather than a non-catalytic one. The L subunit evolved to have a regulatory role, lost catalytic residues more than 130 million years ago before monocots and dicots diverged, and preserved, possibly as a byproduct, the active site domain.
Download or read book Structure Function Relationship Studies of Escherichia Coli ADP glucose Pyrophosphorylase written by Clarisa Maria Bejar and published by . This book was released on 2006 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure Function Relationship of Plant ADP Glucose Pyrophosphorylase written by Ayşe Bengisu Seferoğlu and published by . This book was released on 2014 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comparative Analysis of the Structure and Function Relationship of ADP glucose Pyrophosphorylases written by Jocelyn Reyes Frago and published by . This book was released on 2002 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure function Relationships of Glycogen Branching Enzymes written by Marta Palomo Reixach and published by . This book was released on 2011 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural Analysis of Branching Enzyme and ADP glucose Pyrophosphorylase written by Kim Binderup and published by . This book was released on 2000 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural and Functional Relationships in Prokaryotes written by Larry L. Barton and published by Springer Science & Business Media. This book was released on 2005-11-24 with total page 833 pages. Available in PDF, EPUB and Kindle. Book excerpt: For several decades, bacteria have served as model systems to describe the life p- cesses of growth and metabolism. In addition, it is well recognized that prokaryotes have contributed greatly to the many advances in the areas of ecology, evolution, and biotechnology. This understanding of microorganisms is based on studies of members from both theBacteria andArchaea domains. With each issue of the various scienti?c publications, new characteristics of prokaryotic cells are being reported and it is - portant to place these insights in the context of the appropriate physiological processes. Structural and Functional Relationships in Prokaryotes describes the fundamental physiological processes for members of the Archaea and Bacteria domains. The - ganization of the book re?ects the emphasis that I have used in my 30 years of teaching a course of bacterial physiology. The philosophy used in the preparation of this book is to focus on the fundamental features of prokaryotic physiology and to use these features as the basis for comparative physiology. Even though diverse phenotypes have evolved from myriad genetic possibilities, these prokaryotes display considerable functional similarity and support the premise that there is a unity of physiology in the prokaryotes. The variations observed in the chemical structures and biochemical p- cesses are important in contributing to the persistence of microbial strains in a speci?c environment.
Download or read book Inclusions in Prokaryotes written by Jessup M. Shively and published by Springer Science & Business Media. This book was released on 2006-05-04 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: The new series "Microbiology Monographs" begins with two volumes on intracellular components in prokaryotes. In this first volume, "Inclusions in Prokaryotes", the components, labeled inclusions, are defined as discrete bodies resulting from synthesis of a metabolic product. Research on the biosynthesis and reutilization of the accumulated materials is still in progress, and interest in the inclusions is growing. This comprehensive volume provides historical background and comprehensive reviews of eight well-known prokaryotic inclusions.
Download or read book Photoassimilate Distribution Plants and Crops Source Sink Relationships written by Zamski and published by Routledge. This book was released on 2017-09-29 with total page 928 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adopting an interdisciplinary approach to the study of photoassimilate partitioning and source-sink relationhips, this work details the major aspects of source-sink physiology and metabolism, the integration of individual components and photoassimilate partitioning, and the whole plant source-sink relationships in 16 agriculturally important crops. The work examines in detail the components of carbon partitioning, such as ecology, photosynthesis, loading, transport and anatomy, and discusses the impact of genetic, environmental and agrotechnical factors on the parts of whole plant source-link physiology.
Download or read book Gene Conservation and Exploitation written by J. Perry Gustafson and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: The potato (Solanum tuberosum L. ) tuber is a major food source in many countries of the world, and subsequently potato has been the target of a good deal of effort directed at engineering disease and herbicide tolerance, and improvements in various crop characteristics. Consequently investigations into the regulation of gene expression in tubers is relevant to these endeavours, as tubers are the main target organ for modification of gene expression. We have been interested in the regulation of genes in tubers for these reasons. Morphologically tubers are modified stems, which have enlarged radially by limited cell division and substantial expansion. At the molecular level, tuber development is characterised by a massive increase in starch deposition and the synthesis of a limited number of abundant proteins. These include proteinase inhibitors and a 40kd group of proteins called patatin, which are acyl hydrolases. Together these proteins account for over 50% of tuber proteins (reviewed by Bevan, 1991). The synthesis of these proteins has parallels to the synthesis of other somatic storage proteins, especially the VSP proteins of soybean. In both potato and soybean, removal of the sink for these proteins (tubers and pods, respectively) causes deposition in other tissues (Staswick, 1990). It is hypothesised that transcriptional control of the genes encoding these proteins is regulated in part by source-sink relationships of metabolites or other factors. In the case of VSPs, both amino acid levels and jasmonic acid play a major regulatory role (Staswick et aI.
Download or read book Starch in Food written by Ann-Charlotte Eliasson and published by CRC Press. This book was released on 2004-09-20 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt: Starch is an important ingredient for the food industry and researchers are making progress in discovering new details about its structure, functionality and impact on our health. Starch in Food reviews starch structure and functionality and the growing range of starch ingredients used to improve the nutritional and sensory quality of food. Starch in Food begins by illustrating how plant starch can be analyzed and modified, with chapters on plant starch synthesis, starch bioengineering, and starch-acting enzymes. It examines the sources of starch, from wheat and potatoes to rice, corn, and tropical supplies. The book looks at modified starches and the stability of frozen foods, starch lipid interactions and starch-based microencapsulation. It covers starch as a functional food, investigating the impact of starch on physical and mental performance, detecting nutritional starch fractions, and analyzing starch digestion. Starch in Food is an authoritative and indispensable reference, edited by a leader in the field with contributions from experts worldwide.
Download or read book A Molecular Approach To Primary Metabolism In Higher Plants written by Christine Foyer and published by CRC Press. This book was released on 1997-08-08 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discusses and explains the major advances that the new technology of applying molecular genetic techniques of modifying carbon and nitrogen in plants has provided, giving insights into its applications for the benefits of agriculture, the environment and man. The text is divided into three sections, the first focusing on primary nitrogen and carbon
Download or read book Seed Development and Germination written by Jaime Kigel and published by Routledge. This book was released on 2017-11-01 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text is intended for plant physiologists, molecular biologists, biochemists, biotechnologists, geneticists, horticulturalists, agromnomists and botanists, and upper-level undergraduate and graduate students in these disciplines. It integrates advances in the diverse and rapidly-expanding field of seed science, from ecological and demographic aspects of seed production, dispersal and germination, to the molecular biology of seed development. The book offers a broad, multidisciplinary approach that covers both theoretical and applied knowledge.
Download or read book Starch in Food written by Malin Sjöö and published by Woodhead Publishing. This book was released on 2017-11-25 with total page 918 pages. Available in PDF, EPUB and Kindle. Book excerpt: Starch in Food: Structure, Function and Applications, Second Edition, reviews starch structure, functionality and the growing range of starch ingredients used to improve the nutritional and sensory quality of food. The new edition is fully updated and brings new chapters on starch and health, isolation, processing and functional properties of starch. Part One illustrates how plant starch can be analyzed and modified, with chapters on plant starch synthesis, starch bioengineering and starch-acting enzymes. Part Two examines the sources of starch, from wheat and potato, to rice, corn and tropical supplies. Part Three looks at starch as an ingredient and how it is used in the food industry, with chapters on modified starches and the stability of frozen foods, starch-lipid interactions and starch-based microencapsulation. Part Four covers starch as a functional food, investigating the impact of starch on physical and mental performance, detecting nutritional starch fractions and analyzing starch digestion. The book is a standard reference for those working in the food industry, especially to starch scientists, food researchers, post-docs, practitioners in the starch area and students. - Completely revised and updated with an overview of the latest developments in isolation, processing, functional properties and health attributes of starch - Reviews starch structure and functionality - Extensive coverage of the growing range of starch ingredients - Examines how starch ingredients are used to improve the nutritional and sensory quality of food
Download or read book Prokaryotic Structure and Function written by Society for General Microbiology. Symposium and published by Cambridge University Press. This book was released on 1992-02-20 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book evaluates the increasing wealth of knowledge that has accumulated concerning the regulation of synthesis and assembly of structural components of the bacterial cell. It is now possible in many cases to trace the exact sequence of events triggered by a change in the physical or chemical environment of a bacterial cell, for instance, signaling, gene expression, transport of the gene product to its correct location, and assembly into a functional structure. The scope of this volume is broad, ranging from the organization of the nuclear material itself to the sequence of events leading to differentiation and development; from the synthesis of intracellular storage material to the assembly of specialized photosynthetic membranes, periplasmic electron transfer chains, and heat-resistant spores.
Download or read book Starch Basic Science to Biotechnology written by and published by Academic Press. This book was released on 1998-08-10 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents the physiological and biochemical aspects of storage carbohydrates, or starch granules, in plants. This up-to-date and thorough resource carefully integrates fundamental knowledge with the most recent information on the starch granule. It discusses the chemistry of the starch granule and the biochemistry, molecular biology, plant physiology, and genetics of plant starch synthesis. The books also describes the implications of these studies for theseed, biotechnology, and modified starch industries. - Written for a broad readership - Emphasizes the recent findings on the properties of starch biosynthetic enzymes and on studies describing their localization - Details the implications these studies have on the seed, biotechnology, and modified starch industries - Includes numerous references to the original literature - Introduces the reader to the most important individuals and discoveries in the field
Download or read book Energy Research Abstracts written by and published by . This book was released on 1994-06 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
