The Biosynthesis of Polysaccharides

This book is directed towards them, not with the intention that it should compete with existing text books, or simply be an elementary introduction, but with the intent that it should provide a bridge between the rather disparate and ...

Author: R. W. Stoddart

Publisher: Springer Science & Business Media

ISBN: 1461598737

Category: Science

Page: 356

View: 966

For many years studies of the structure and biosynthesis of saccharides formed a specialised and somewhat abstruse part of biochemistry, with little or no place in molecular biology. In recent years this has changed profoundly, as has the character of much of carbohydrate biochemistry. Saccharides are now seen as generally possessing specific structures, which are potentially informational-though there is little firm evidence, as yet, as to the nature and expression of this information. Biosynthetic studies, especially upon glyco proteins, have provided major new insights into the ways by which specific sugar sequences can be assembled and the relationship of this to membranes and membrane flow. While the study of polysaccharide 'biosynthesis has developed more slowly, its future progress will be profoundly affected by the new knowledge of glycoproteins and this, in turn, will have major implications in the understanding of biological matrices and microenvironments. With this rapid growth and change, ever more scientists - of increasingly diverse backgrounds - are needing to understand something of carbohydrate biochemistry. This book is directed towards them, not with the intention that it should compete with existing text books, or simply be an elementary introduction, but with the intent that it should provide a bridge between the rather disparate and diverging lines of development in the subject and to bring out the important principles of saccharide assembly that are emerging.


Biogenesis Of Plant Cell Wall Polysaccharides

Organized into 17 chapters, this book details the progress and understanding regarding the biosynthesis of cell wall components and the assembly of these components in the wall.

Author: Frank Loewus

Publisher: Elsevier

ISBN: 0323152465

Category: Science

Page: 394

View: 765

Biogenesis of Plant Cell Wall Polysaccharides contains the proceedings of a 1972 symposium on Biogenesis of Plant Cell Wall Polysaccharides held at the 164th National Meeting of the American Chemical Society, New York, New York. The symposium focuses on a broad range of interest from structural to functional aspects of cell wall polysaccharide biosynthesis in algae as well as in higher plants. Organized into 17 chapters, this book details the progress and understanding regarding the biosynthesis of cell wall components and the assembly of these components in the wall. It encompasses topics on cell wall polysaccharides, UDP-D-glucuronic acid pyrophosphorylase, and D-xylose. This reference also tackles the UDP-D-glucuronic acid, L-arabinose, D-apiose, and carbohydrate polymers. Furthermore, it explains other topics, such as on extensin, hydroxyproline-rich glycoprotein, cellulose, and polygalacturonic acid.


The Polysaccharides

Enzymes metabolizing polysaccharides and their application to the analysis of structure and function of glycans; Biosynthesis of polysaccharides; Starch; Glycogen: a structural viewpoint; Mammalian glycosaminoglycans; Chitin.

Author: Gerald O. Aspinall

Publisher: New York : Academic Press

ISBN:

Category: Science

Page: 470

View: 472

Enzymes metabolizing polysaccharides and their application to the analysis of structure and function of glycans; Biosynthesis of polysaccharides; Starch; Glycogen: a structural viewpoint; Mammalian glycosaminoglycans; Chitin.


Annual Plant Reviews Plant Polysaccharides

All libraries in universities and research establishments where plant sciences, agriculture, biological, biochemical and molecular sciences are studied and taught should have copies of this important volume.

Author: Peter Ulvskov

Publisher: John Wiley & Sons

ISBN: 9781444391008

Category: Science

Page: 504

View: 375

Plant Polysaccharides, an exceptional new volume in Wiley-Blackwell’s successful Annual Plant Reviews series, covers the polysaccharides and proteins that form the fundamental architecture of the plant cell wall, and the genes that encode the cellular machinery that synthesizes them. The volume focuses on the evolution of the many families of genes whose products are required to make a particular kind of polysaccharide, bringing attention to the specific biochemical properties of the proteins to the level of kinds of sugar linkages they make. Beautifully illustrated in full colour throughout, this exceptional new volume provides cutting edge up-to-date information on such important topics as cell wall biology, composition and biosynthesis, glycosyltransferases, hydroxyproline-rich glycoproteins, enzymatic modification of plant cell wall polysaccharides, glycan engineering in transgenic plants, and polysaccharide nanobiotechnology. Drawing together some of the world’s leading experts in these areas, the editor, Peter Ulvskov, has provided a landmark volume that is essential reading for plant and crop scientists, biochemists, molecular biologists and geneticists. All libraries in universities and research establishments where plant sciences, agriculture, biological, biochemical and molecular sciences are studied and taught should have copies of this important volume.


Differential Biosynthesis and Control of Two Discrete Unipolar Polysaccharide Adhesins in Agrobacterium Tumefaciens

Bacterial attachment is a critical first step in the formation of complex, matrix-enmeshed, microbial communities called biofilms.

Author: Maureen Chinwe Onyeziri

Publisher:

ISBN:

Category: Agrobacterium tumefaciens

Page: 0

View: 859

Bacterial attachment is a critical first step in the formation of complex, matrix-enmeshed, microbial communities called biofilms. In Agrobacterium tumefaciens, secretion of the unipolar polysaccharide (UPP) adhesin is necessary for stable polar attachment that drives biofilm formation on a variety of surfaces, but this UPP is neither produced by cells grown in dispersed culture nor by bacterial colonies grown on solid media. Elevation of intracellular levels of the second messenger cyclic diguanosine monophosphate (cdGMP) increases UPP production and bypasses the surface contact-dependence of UPP synthesis, thereby promoting UPP secretion by planktonic cells and in bacterial colonies. Multiple genes involved in UPP biosynthesis have been identified and their products suggest that they constitute a Wzx/Wzy-type polysaccharide biosynthesis pathway. Preliminary data suggest that the UPP structure may be composed of at least two distinct polysaccharides, with one polysaccharide containing N-acetylglucosamine (GlcN) and the other containing N-acetyl galactosamine (GalN) as determined by fluorescent short-term binding of UPP with the lectins Wheat Germ Agglutinin (WGA; specific to GlcN) and Dolichos biflorus Agglutinin (DBA; specific to GalN). Wzy-type polymerase homologs UppY and UppW appear to specify the DBA- and WGA-binding polysaccharides (UPPGalN and UPPGlcN) respectively. Two Wzx-type flippase homologs, UppX and UppV are likely to catalyze the transfer of polysaccharide subunits attached to a lipid carrier on the intracellular leaflet of the cytoplasmic membrane across the bilayer to the periplasmic leaflet where they can be polymerized in the periplasm by the action of the Wzy-type polymerase homologs. In addition to UPP, A. tumefaciens also secretes four other exopolysaccharides (EPS): cellulose (C), curdlan (D), Beta-1,2-glucan (G), and succinoglycan (S), all of which contribute in varying degrees to biofilm formation. In my dissertation studies, I built upon previous work that identified the UppY and UppW polymerase homologs and their specificity for the different UPP polysaccharides. Initial genetic analysis of UPP biosynthesis, to which I contributed, had identified a large number of genes required for UPP production, defining a large and complex UPP pathway. To further delineate the dual polysaccharide pathways, I engineered independent single deletion mutants of uppY and uppW that have elevated levels of cdGMP and therefore generate colonies that pigment dark red on solid media containing the polysaccharide-reactive dye Congo-red. Transposon mutagenesis was used to identify mutants that had decreased Congo-red phenotypes, and en masse sequencing was used to map the transposon insertions. This analysis revealed that many of the requisite steps of the UppY- and UppW-dependent pathways share the same biosynthetic components to produce the two discrete polysaccharides. One striking exception is the UppG glycosyl hydrolase which only impacts the UppW-dependent UPPGlcN polysaccharide. The mechanism by which these pathways diverge may to be gated by the activity of UppG.